mirror of
https://github.com/RPCS3/llvm.git
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7e76879901
Summary:
Motivation: fix PR31181 without regression (the actual fix is still in
progress). However, the actual content of PR31181 is not relevant
here.
This change makes poison propagation more aggressive in the following
cases:
1. poision * Val == poison, for any Val. In particular, this changes
existing intentional and documented behavior in these two cases:
a. Val is 0
b. Val is 2^k * N
2. poison << Val == poison, for any Val
3. getelementptr is poison if any input is poison
I think all of these are justified (and are axiomatically true in the
new poison / undef model):
1a: we need poison * 0 to be poison to allow transforms like these:
A * (B + C) ==> A * B + A * C
If poison * 0 were 0 then the above transform could not be allowed
since e.g. we could have A = poison, B = 1, C = -1, making the LHS
poison * (1 + -1) = poison * 0 = 0
and the RHS
poison * 1 + poison * -1 = poison + poison = poison
1b: we need e.g. poison * 4 to be poison since we want to allow
A * 4 ==> A + A + A + A
If poison * 4 were a value with all of their bits poison except the
last four; then we'd not be able to do this transform since then if A
were poison the LHS would only be "partially" poison while the RHS
would be "full" poison.
2: Same reasoning as (1b), we'd like have the following kinds
transforms be legal:
A << 1 ==> A + A
Reviewers: majnemer, efriedma
Subscribers: mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D30185
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295809 91177308-0d34-0410-b5e6-96231b3b80d8
736 lines
21 KiB
LLVM
736 lines
21 KiB
LLVM
; RUN: opt < %s -S -analyze -scalar-evolution | FileCheck %s
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; Positive and negative tests for inferring flags like nsw from
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; reasoning about how a poison value from overflow would trigger
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; undefined behavior.
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define void @foo() {
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ret void
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}
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; Example where an add should get the nsw flag, so that a sext can be
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; distributed over the add.
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define void @test-add-nsw(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-add-nsw
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nsw>
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%index32 = add nsw i32 %i, %offset
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; CHECK: %index64 =
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; CHECK: --> {(sext i32 %offset to i64),+,1}<nsw>
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%index64 = sext i32 %index32 to i64
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%ptr = getelementptr inbounds float, float* %input, i64 %index64
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%nexti = add nsw i32 %i, 1
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%f = load float, float* %ptr, align 4
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call void @foo()
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; Example where an add should get the nuw flag.
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define void @test-add-nuw(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-add-nuw
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nuw>
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%index32 = add nuw i32 %i, %offset
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%ptr = getelementptr inbounds float, float* %input, i32 %index32
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%nexti = add nuw i32 %i, 1
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%f = load float, float* %ptr, align 4
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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define void @test-add-nuw-from-icmp(float* %input, i32 %offset,
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i32 %numIterations) {
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; CHECK-LABEL: @test-add-nuw-from-icmp
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nuw>
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%index32 = add nuw i32 %i, %offset
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%cmp = icmp sgt i32 %index32, 0
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%cmp.idx = sext i1 %cmp to i32
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%ptr = getelementptr inbounds float, float* %input, i32 %cmp.idx
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%nexti = add nuw i32 %i, 1
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%f = load float, float* %ptr, align 4
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; With no load to trigger UB from poison, we cannot infer nsw.
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define void @test-add-no-load(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-add-no-load
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nw>
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%index32 = add nsw i32 %i, %offset
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%ptr = getelementptr inbounds float, float* %input, i32 %index32
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%nexti = add nuw i32 %i, 1
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; The current code is only supposed to look at the loop header, so
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; it should not infer nsw in this case, as that would require looking
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; outside the loop header.
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define void @test-add-not-header(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-add-not-header
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop2 ], [ 0, %entry ]
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br label %loop2
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loop2:
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nw>
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%index32 = add nsw i32 %i, %offset
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%ptr = getelementptr inbounds float, float* %input, i32 %index32
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%nexti = add nsw i32 %i, 1
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%f = load float, float* %ptr, align 4
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; Same thing as test-add-not-header, but in this case only the load
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; instruction is outside the loop header.
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define void @test-add-not-header2(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-add-not-header2
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop2 ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nsw>
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%index32 = add nsw i32 %i, %offset
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%ptr = getelementptr inbounds float, float* %input, i32 %index32
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%nexti = add nsw i32 %i, 1
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br label %loop2
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loop2:
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%f = load float, float* %ptr, align 4
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; Similar to test-add-not-header, but in this case the load
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; instruction may not be executed.
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define void @test-add-not-header3(float* %input, i32 %offset, i32 %numIterations,
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i1* %cond_buf) {
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; CHECK-LABEL: @test-add-not-header3
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop2 ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nw>
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%index32 = add nsw i32 %i, %offset
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%ptr = getelementptr inbounds float, float* %input, i32 %index32
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%nexti = add nsw i32 %i, 1
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%cond = load volatile i1, i1* %cond_buf
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br i1 %cond, label %loop2, label %exit
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loop2:
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%f = load float, float* %ptr, align 4
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; Same thing as test-add-not-header2, except we have a few extra
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; blocks.
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define void @test-add-not-header4(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-add-not-header4
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop2 ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nsw>
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%index32 = add nsw i32 %i, %offset
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%ptr = getelementptr inbounds float, float* %input, i32 %index32
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%nexti = add nsw i32 %i, 1
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br label %loop3
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loop3:
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br label %loop4
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loop4:
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br label %loop2
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loop2:
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%f = load float, float* %ptr, align 4
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; Demonstrate why we need a Visited set in llvm::isKnownNotFullPoison.
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define void @test-add-not-header5(float* %input, i32 %offset) {
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; CHECK-LABEL: @test-add-not-header5
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nw>
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%index32 = add nsw i32 %i, %offset
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%ptr = getelementptr inbounds float, float* %input, i32 %index32
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%nexti = add nsw i32 %i, 1
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br label %loop
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exit:
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ret void
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}
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; The call instruction makes it not guaranteed that the add will be
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; executed, since it could run forever or throw an exception, so we
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; cannot assume that the UB is realized.
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define void @test-add-call(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-add-call
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nw>
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call void @foo()
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%index32 = add nsw i32 %i, %offset
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%ptr = getelementptr inbounds float, float* %input, i32 %index32
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%nexti = add nsw i32 %i, 1
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%f = load float, float* %ptr, align 4
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; Same issue as test-add-call, but this time the call is between the
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; producer of poison and the load that consumes it.
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define void @test-add-call2(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-add-call2
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nw>
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%index32 = add nsw i32 %i, %offset
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%ptr = getelementptr inbounds float, float* %input, i32 %index32
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%nexti = add nsw i32 %i, 1
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call void @foo()
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%f = load float, float* %ptr, align 4
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; Any poison input makes getelementptr produce poison
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define void @test-gep-propagates-poison(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-gep-propagates-poison
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nsw>
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%index32 = add nsw i32 %i, %offset
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%ptr = getelementptr float, float* %input, i32 %index32
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%nexti = add nsw i32 %i, 1
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%f = load float, float* %ptr, align 4
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; Multiplication by a non-zero constant propagates poison if there is
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; a nuw or nsw flag on the multiplication.
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define void @test-add-mul-propagates(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-add-mul-propagates
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nsw>
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%index32 = add nsw i32 %i, %offset
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%indexmul = mul nuw i32 %index32, 2
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%ptr = getelementptr inbounds float, float* %input, i32 %indexmul
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%nexti = add nsw i32 %i, 1
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%f = load float, float* %ptr, align 4
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; Any poison input to multiplication propages poison.
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define void @test-mul-propagates-poison(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-mul-propagates-poison
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nsw>
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%index32 = add nsw i32 %i, %offset
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%indexmul = mul nsw i32 %index32, %offset
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%ptr = getelementptr inbounds float, float* %input, i32 %indexmul
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%nexti = add nsw i32 %i, 1
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%f = load float, float* %ptr, align 4
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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define void @test-mul-propagates-poison-2(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-mul-propagates-poison-2
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nsw>
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%index32 = add nsw i32 %i, %offset
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%indexmul = mul i32 %index32, 2
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%ptr = getelementptr inbounds float, float* %input, i32 %indexmul
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%nexti = add nsw i32 %i, 1
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%f = load float, float* %ptr, align 4
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; Division by poison triggers UB.
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define void @test-add-div(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-add-div
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %j =
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; CHECK: --> {%offset,+,1}<nsw>
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%j = add nsw i32 %i, %offset
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%q = sdiv i32 %numIterations, %j
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%nexti = add nsw i32 %i, 1
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; Remainder of poison by non-poison divisor does not trigger UB.
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define void @test-add-div2(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-add-div2
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %j =
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; CHECK: --> {%offset,+,1}<nw>
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%j = add nsw i32 %i, %offset
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%q = sdiv i32 %j, %numIterations
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%nexti = add nsw i32 %i, 1
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; Store to poison address triggers UB.
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define void @test-add-store(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-add-store
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entry:
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br label %loop
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loop:
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%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
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; CHECK: %index32 =
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; CHECK: --> {%offset,+,1}<nsw>
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%index32 = add nsw i32 %i, %offset
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%ptr = getelementptr inbounds float, float* %input, i32 %index32
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%nexti = add nsw i32 %i, 1
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store float 1.0, float* %ptr, align 4
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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exit:
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ret void
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}
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; Three sequential adds where the middle add should have nsw. There is
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; a special case for sequential adds and this test covers that. We have to
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; put the final add first in the program since otherwise the special case
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; is not triggered, hence the strange basic block ordering.
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define void @test-add-twice(float* %input, i32 %offset, i32 %numIterations) {
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; CHECK-LABEL: @test-add-twice
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entry:
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br label %loop
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loop2:
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; CHECK: %seq =
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; CHECK: --> {(2 + %offset),+,1}<nw>
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%seq = add nsw nuw i32 %index32, 1
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%exitcond = icmp eq i32 %nexti, %numIterations
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br i1 %exitcond, label %exit, label %loop
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loop:
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%i = phi i32 [ %nexti, %loop2 ], [ 0, %entry ]
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%j = add nsw i32 %i, 1
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; CHECK: %index32 =
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; CHECK: --> {(1 + %offset)<nsw>,+,1}<nsw>
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%index32 = add nsw i32 %j, %offset
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%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nsw i32 %i, 1
|
|
store float 1.0, float* %ptr, align 4
|
|
br label %loop2
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a mul should get the nsw flag, so that a sext can be
|
|
; distributed over the mul.
|
|
define void @test-mul-nsw(float* %input, i32 %stride, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-mul-nsw
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {0,+,%stride}<nsw>
|
|
%index32 = mul nsw i32 %i, %stride
|
|
|
|
; CHECK: %index64 =
|
|
; CHECK: --> {0,+,(sext i32 %stride to i64)}<nsw>
|
|
%index64 = sext i32 %index32 to i64
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i64 %index64
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a mul should get the nuw flag.
|
|
define void @test-mul-nuw(float* %input, i32 %stride, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-mul-nuw
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {0,+,%stride}<nuw>
|
|
%index32 = mul nuw i32 %i, %stride
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nuw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a shl should get the nsw flag, so that a sext can be
|
|
; distributed over the shl.
|
|
define void @test-shl-nsw(float* %input, i32 %start, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-shl-nsw
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ %start, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {(256 * %start),+,256}<nsw>
|
|
%index32 = shl nsw i32 %i, 8
|
|
|
|
; CHECK: %index64 =
|
|
; CHECK: --> {(sext i32 (256 * %start) to i64),+,256}<nsw>
|
|
%index64 = sext i32 %index32 to i64
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i64 %index64
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a shl should get the nuw flag.
|
|
define void @test-shl-nuw(float* %input, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-shl-nuw
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {0,+,512}<nuw>
|
|
%index32 = shl nuw i32 %i, 9
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nuw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a sub should *not* get the nsw flag, because of how
|
|
; scalar evolution represents A - B as A + (-B) and -B can wrap even
|
|
; in cases where A - B does not.
|
|
define void @test-sub-no-nsw(float* %input, i32 %start, i32 %sub, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-sub-no-nsw
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ %start, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {((-1 * %sub) + %start),+,1}<nw>
|
|
%index32 = sub nsw i32 %i, %sub
|
|
%index64 = sext i32 %index32 to i64
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i64 %index64
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a sub should get the nsw flag as the RHS cannot be the
|
|
; minimal signed value.
|
|
define void @test-sub-nsw(float* %input, i32 %start, i32 %sub, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-sub-nsw
|
|
entry:
|
|
%halfsub = ashr i32 %sub, 1
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ %start, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {((-1 * %halfsub)<nsw> + %start)<nsw>,+,1}<nsw>
|
|
%index32 = sub nsw i32 %i, %halfsub
|
|
%index64 = sext i32 %index32 to i64
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i64 %index64
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Example where a sub should get the nsw flag, since the LHS is non-negative,
|
|
; which implies that the RHS cannot be the minimal signed value.
|
|
define void @test-sub-nsw-lhs-non-negative(float* %input, i32 %sub, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-sub-nsw-lhs-non-negative
|
|
entry:
|
|
br label %loop
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
|
|
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {(-1 * %sub),+,1}<nsw>
|
|
%index32 = sub nsw i32 %i, %sub
|
|
|
|
; CHECK: %index64 =
|
|
; CHECK: --> {(sext i32 (-1 * %sub) to i64),+,1}<nsw>
|
|
%index64 = sext i32 %index32 to i64
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i64 %index64
|
|
%nexti = add nsw i32 %i, 1
|
|
%f = load float, float* %ptr, align 4
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
; Two adds with a sub in the middle and the sub should have nsw. There is
|
|
; a special case for sequential adds/subs and this test covers that. We have to
|
|
; put the final add first in the program since otherwise the special case
|
|
; is not triggered, hence the strange basic block ordering.
|
|
define void @test-sub-with-add(float* %input, i32 %offset, i32 %numIterations) {
|
|
; CHECK-LABEL: @test-sub-with-add
|
|
entry:
|
|
br label %loop
|
|
loop2:
|
|
; CHECK: %seq =
|
|
; CHECK: --> {(2 + (-1 * %offset)),+,1}<nw>
|
|
%seq = add nsw nuw i32 %index32, 1
|
|
%exitcond = icmp eq i32 %nexti, %numIterations
|
|
br i1 %exitcond, label %exit, label %loop
|
|
|
|
loop:
|
|
%i = phi i32 [ %nexti, %loop2 ], [ 0, %entry ]
|
|
|
|
%j = add nsw i32 %i, 1
|
|
; CHECK: %index32 =
|
|
; CHECK: --> {(1 + (-1 * %offset))<nsw>,+,1}<nsw>
|
|
%index32 = sub nsw i32 %j, %offset
|
|
|
|
%ptr = getelementptr inbounds float, float* %input, i32 %index32
|
|
%nexti = add nsw i32 %i, 1
|
|
store float 1.0, float* %ptr, align 4
|
|
br label %loop2
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
|
|
; Subtraction of two recurrences. The addition in the SCEV that this
|
|
; maps to is NSW, but the negation of the RHS does not since that
|
|
; recurrence could be the most negative representable value.
|
|
define void @subrecurrences(i32 %outer_l, i32 %inner_l, i32 %val) {
|
|
; CHECK-LABEL: @subrecurrences
|
|
entry:
|
|
br label %outer
|
|
|
|
outer:
|
|
%o_idx = phi i32 [ 0, %entry ], [ %o_idx.inc, %outer.be ]
|
|
%o_idx.inc = add nsw i32 %o_idx, 1
|
|
%cond = icmp eq i32 %o_idx, %val
|
|
br i1 %cond, label %inner, label %outer.be
|
|
|
|
inner:
|
|
%i_idx = phi i32 [ 0, %outer ], [ %i_idx.inc, %inner ]
|
|
%i_idx.inc = add nsw i32 %i_idx, 1
|
|
; CHECK: %v =
|
|
; CHECK-NEXT: --> {{[{][{]}}-1,+,-1}<nw><%outer>,+,1}<nsw><%inner>
|
|
%v = sub nsw i32 %i_idx, %o_idx.inc
|
|
%forub = udiv i32 1, %v
|
|
%cond2 = icmp eq i32 %i_idx, %inner_l
|
|
br i1 %cond2, label %outer.be, label %inner
|
|
|
|
outer.be:
|
|
%cond3 = icmp eq i32 %o_idx, %outer_l
|
|
br i1 %cond3, label %exit, label %outer
|
|
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
|
|
; PR28932: Don't assert on non-SCEV-able value %2.
|
|
%struct.anon = type { i8* }
|
|
@a = common global %struct.anon* null, align 8
|
|
@b = common global i32 0, align 4
|
|
declare { i32, i1 } @llvm.ssub.with.overflow.i32(i32, i32)
|
|
declare void @llvm.trap()
|
|
define i32 @pr28932() {
|
|
entry:
|
|
%.pre = load %struct.anon*, %struct.anon** @a, align 8
|
|
%.pre7 = load i32, i32* @b, align 4
|
|
br label %for.cond
|
|
|
|
for.cond: ; preds = %cont6, %entry
|
|
%0 = phi i32 [ %3, %cont6 ], [ %.pre7, %entry ]
|
|
%1 = phi %struct.anon* [ %.ph, %cont6 ], [ %.pre, %entry ]
|
|
%tobool = icmp eq %struct.anon* %1, null
|
|
%2 = tail call { i32, i1 } @llvm.ssub.with.overflow.i32(i32 %0, i32 1)
|
|
%3 = extractvalue { i32, i1 } %2, 0
|
|
%4 = extractvalue { i32, i1 } %2, 1
|
|
%idxprom = sext i32 %3 to i64
|
|
%5 = getelementptr inbounds %struct.anon, %struct.anon* %1, i64 0, i32 0
|
|
%6 = load i8*, i8** %5, align 8
|
|
%7 = getelementptr inbounds i8, i8* %6, i64 %idxprom
|
|
%8 = load i8, i8* %7, align 1
|
|
br i1 %tobool, label %if.else, label %if.then
|
|
|
|
if.then: ; preds = %for.cond
|
|
br i1 %4, label %trap, label %cont6
|
|
|
|
trap: ; preds = %if.else, %if.then
|
|
tail call void @llvm.trap()
|
|
unreachable
|
|
|
|
if.else: ; preds = %for.cond
|
|
br i1 %4, label %trap, label %cont1
|
|
|
|
cont1: ; preds = %if.else
|
|
%conv5 = sext i8 %8 to i64
|
|
%9 = inttoptr i64 %conv5 to %struct.anon*
|
|
store %struct.anon* %9, %struct.anon** @a, align 8
|
|
br label %cont6
|
|
|
|
cont6: ; preds = %cont1, %if.then
|
|
%.ph = phi %struct.anon* [ %9, %cont1 ], [ %1, %if.then ]
|
|
store i32 %3, i32* @b, align 4
|
|
br label %for.cond
|
|
}
|