Files
llvm/test/Transforms/LICM/guards.ll
T
Max Kazantsev 8e59cd1915 [LICM] Hoist guards from non-header blocks
This patch relaxes overconservative checks on whether or not we could write
memory before we execute an instruction. This allows us to hoist guards out of
loops even if they are not in the header block.

Differential Revision: https://reviews.llvm.org/D50891
Reviewed By: fedor.sergeev



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346643 91177308-0d34-0410-b5e6-96231b3b80d8
2018-11-12 09:29:58 +00:00

415 lines
10 KiB
LLVM

; REQUIRES: asserts
; RUN: opt -licm -basicaa -ipt-expensive-asserts=true < %s -S | FileCheck %s
; RUN: opt -aa-pipeline=basic-aa -passes='require<aa>,require<targetir>,require<scalar-evolution>,require<opt-remark-emit>,loop(licm)' -ipt-expensive-asserts=true < %s -S | FileCheck %s
; Hoist guard and load.
define void @test1(i1 %cond, i32* %ptr) {
; CHECK-LABEL: @test1(
; CHECK-LABEL: entry:
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %cond)
; CHECK: %val = load i32, i32* %ptr
; CHECK-LABEL: loop:
entry:
br label %loop
loop:
%x = phi i32 [ 0, %entry ], [ %x.inc, %loop ]
call void (i1, ...) @llvm.experimental.guard(i1 %cond) ["deopt" (i32 0)]
%val = load i32, i32* %ptr
%x.inc = add i32 %x, %val
br label %loop
}
; Can't hoist over a side effect
define void @test2(i1 %cond, i32* %ptr) {
; CHECK-LABEL: @test2(
; CHECK-LABEL: entry:
; CHECK-LABEL: loop:
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %cond)
; CHECK: %val = load i32, i32* %ptr
entry:
br label %loop
loop:
%x = phi i32 [ 0, %entry ], [ %x.inc, %loop ]
store i32 0, i32* %ptr
call void (i1, ...) @llvm.experimental.guard(i1 %cond) ["deopt" (i32 0)]
%val = load i32, i32* %ptr
%x.inc = add i32 %x, %val
br label %loop
}
; Can't hoist over a side effect
define void @test2b(i1 %cond, i32* %ptr) {
; CHECK-LABEL: @test2b(
; CHECK-LABEL: entry:
; CHECK-LABEL: loop:
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %cond)
; CHECK: %val = load i32, i32* %ptr
entry:
br label %loop
loop:
%x = phi i32 [ 0, %entry ], [ %x.inc, %loop ]
%p2 = getelementptr i32, i32* %ptr, i32 1
store i32 0, i32* %p2
call void (i1, ...) @llvm.experimental.guard(i1 %cond) ["deopt" (i32 0)]
%val = load i32, i32* %ptr
%x.inc = add i32 %x, %val
br label %loop
}
; Hoist guard. Cannot hoist load because of aliasing.
define void @test3(i1 %cond, i32* %ptr) {
; CHECK-LABEL: @test3(
; CHECK-LABEL: entry:
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %cond)
; CHECK-LABEL: loop:
; CHECK: %val = load i32, i32* %ptr
; CHECK: store i32 0, i32* %ptr
entry:
br label %loop
loop:
%x = phi i32 [ 0, %entry ], [ %x.inc, %loop ]
call void (i1, ...) @llvm.experimental.guard(i1 %cond) ["deopt" (i32 0)]
%val = load i32, i32* %ptr
store i32 0, i32* %ptr
%x.inc = add i32 %x, %val
br label %loop
}
define void @test4(i1 %c, i32* %p) {
; CHECK-LABEL: @test4(
; CHECK-LABEL: entry:
; CHECK: %a = load i32, i32* %p
; CHECK: %invariant_cond = icmp ne i32 %a, 100
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond)
; CHECK-LABEL: loop:
; CHECK-LABEL: backedge:
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
%iv.next = add i32 %iv, 1
br i1 %c, label %if.true, label %if.false
if.true:
br label %backedge
if.false:
br label %backedge
backedge:
%a = load i32, i32* %p
%invariant_cond = icmp ne i32 %a, 100
call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond) [ "deopt"() ]
%loop_cond = icmp slt i32 %iv.next, 1000
br i1 %loop_cond, label %loop, label %exit
exit:
ret void
}
; Do not hoist across a conditionally executed side effect.
define void @test4a(i1 %c, i32* %p, i32* %q) {
; CHECK-LABEL: @test4a(
; CHECK-LABEL: entry:
; CHECK-LABEL: loop:
; CHECK-LABEL: if.true:
; CHECK: store
; CHECK-LABEL: backedge:
; CHECK: %a = load i32, i32* %p
; CHECK: %invariant_cond = icmp ne i32 %a, 100
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond)
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
%iv.next = add i32 %iv, 1
br i1 %c, label %if.true, label %if.false
if.true:
store i32 123, i32* %q
br label %backedge
if.false:
br label %backedge
backedge:
%a = load i32, i32* %p
%invariant_cond = icmp ne i32 %a, 100
call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond) [ "deopt"() ]
%loop_cond = icmp slt i32 %iv.next, 1000
br i1 %loop_cond, label %loop, label %exit
exit:
ret void
}
; Do not hoist a conditionally executed guard.
define void @test4b(i1 %c, i32* %p, i32* %q) {
; CHECK-LABEL: @test4b(
; CHECK-LABEL: entry:
; CHECK-LABEL: loop:
; CHECK-LABEL: if.true:
; CHECK: %a = load i32, i32* %p
; CHECK: %invariant_cond = icmp ne i32 %a, 100
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond)
; CHECK-LABEL: backedge:
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
%iv.next = add i32 %iv, 1
br i1 %c, label %if.true, label %if.false
if.true:
%a = load i32, i32* %p
%invariant_cond = icmp ne i32 %a, 100
call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond) [ "deopt"() ]
br label %backedge
if.false:
br label %backedge
backedge:
%loop_cond = icmp slt i32 %iv.next, 1000
br i1 %loop_cond, label %loop, label %exit
exit:
ret void
}
; Check that we don't hoist across a store in the header.
define void @test4c(i1 %c, i32* %p, i8* noalias %s) {
; CHECK-LABEL: @test4c(
; CHECK-LABEL: entry:
; CHECK: %a = load i32, i32* %p
; CHECK: %invariant_cond = icmp ne i32 %a, 100
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond)
; CHECK-LABEL: loop:
; CHECK-LABEL: backedge:
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
%iv.next = add i32 %iv, 1
store i8 0, i8* %s
br i1 %c, label %if.true, label %if.false
if.true:
br label %backedge
if.false:
br label %backedge
backedge:
%a = load i32, i32* %p
%invariant_cond = icmp ne i32 %a, 100
call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond) [ "deopt"() ]
%loop_cond = icmp slt i32 %iv.next, 1000
br i1 %loop_cond, label %loop, label %exit
exit:
ret void
}
; Check that we don't hoist across a store in a conditionally execute block.
define void @test4d(i1 %c, i32* %p, i8* noalias %s) {
; CHECK-LABEL: @test4d(
; CHECK-LABEL: entry:
; CHECK: %a = load i32, i32* %p
; CHECK: %invariant_cond = icmp ne i32 %a, 100
; CHECK-LABEL: loop:
; CHECK-LABEL: backedge:
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond)
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
%iv.next = add i32 %iv, 1
br i1 %c, label %if.true, label %if.false
if.true:
store i8 0, i8* %s
br label %backedge
if.false:
br label %backedge
backedge:
%a = load i32, i32* %p
%invariant_cond = icmp ne i32 %a, 100
call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond) [ "deopt"() ]
%loop_cond = icmp slt i32 %iv.next, 1000
br i1 %loop_cond, label %loop, label %exit
exit:
ret void
}
; Check that we don't hoist across a store before the guard in the backedge.
define void @test4e(i1 %c, i32* %p, i8* noalias %s) {
; CHECK-LABEL: @test4e(
; CHECK-LABEL: entry:
; CHECK: %a = load i32, i32* %p
; CHECK: %invariant_cond = icmp ne i32 %a, 100
; CHECK: store i8 0, i8* %s
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond)
; CHECK-LABEL: loop:
; CHECK-LABEL: backedge:
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
%iv.next = add i32 %iv, 1
br i1 %c, label %if.true, label %if.false
if.true:
br label %backedge
if.false:
br label %backedge
backedge:
%a = load i32, i32* %p
%invariant_cond = icmp ne i32 %a, 100
store i8 0, i8* %s
call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond) [ "deopt"() ]
%loop_cond = icmp slt i32 %iv.next, 1000
br i1 %loop_cond, label %loop, label %exit
exit:
ret void
}
; Check that we can hoist the guard in spite of store which happens after.
define void @test4f(i1 %c, i32* %p, i8* noalias %s) {
; CHECK-LABEL: @test4f(
; CHECK-LABEL: entry:
; CHECK: %a = load i32, i32* %p
; CHECK: %invariant_cond = icmp ne i32 %a, 100
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond)
; CHECK-LABEL: loop:
; CHECK-LABEL: backedge:
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
%iv.next = add i32 %iv, 1
br i1 %c, label %if.true, label %if.false
if.true:
br label %backedge
if.false:
br label %backedge
backedge:
%a = load i32, i32* %p
%invariant_cond = icmp ne i32 %a, 100
call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond) [ "deopt"() ]
store i8 0, i8* %s
%loop_cond = icmp slt i32 %iv.next, 1000
br i1 %loop_cond, label %loop, label %exit
exit:
ret void
}
; Do not hoist an invariant guard across a variant guard.
define void @test5(i1 %c, i32* %p, i32* %q) {
; CHECK-LABEL: @test5(
; CHECK-LABEL: entry:
; CHECK: %a = load i32, i32* %p
; CHECK: %invariant_cond = icmp ne i32 %a, 100
; CHECK-LABEL: loop:
; CHECK: %variant_cond = icmp ne i32 %a, %iv
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %variant_cond)
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond)
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
%iv.next = add i32 %iv, 1
%a = load i32, i32* %p
%invariant_cond = icmp ne i32 %a, 100
%variant_cond = icmp ne i32 %a, %iv
call void (i1, ...) @llvm.experimental.guard(i1 %variant_cond) [ "deopt"() ]
call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond) [ "deopt"() ]
br label %backedge
backedge:
%loop_cond = icmp slt i32 %iv.next, 1000
br i1 %loop_cond, label %loop, label %exit
exit:
ret void
}
; Hoist an invariant guard, leave the following variant guard in the loop.
define void @test5a(i1 %c, i32* %p, i32* %q) {
; CHECK-LABEL: @test5a(
; CHECK-LABEL: entry:
; CHECK: %a = load i32, i32* %p
; CHECK: %invariant_cond = icmp ne i32 %a, 100
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond)
; CHECK-LABEL: loop:
; CHECK: %variant_cond = icmp ne i32 %a, %iv
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %variant_cond)
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
%iv.next = add i32 %iv, 1
%a = load i32, i32* %p
%invariant_cond = icmp ne i32 %a, 100
%variant_cond = icmp ne i32 %a, %iv
call void (i1, ...) @llvm.experimental.guard(i1 %invariant_cond) [ "deopt"() ]
call void (i1, ...) @llvm.experimental.guard(i1 %variant_cond) [ "deopt"() ]
br label %backedge
backedge:
%loop_cond = icmp slt i32 %iv.next, 1000
br i1 %loop_cond, label %loop, label %exit
exit:
ret void
}
declare void @llvm.experimental.guard(i1, ...)