llvm/test/Transforms/IndVarSimplify/iv-widen.ll
Wei Mi 334f714ef9 [IndVars] Change the order to compute WidenAddRec in widenIVUse.
When both WidenIV::getWideRecurrence and WidenIV::getExtendedOperandRecurrence
return non-null but different WideAddRec, if getWideRecurrence is called
before getExtendedOperandRecurrence, we won't bother to call
getExtendedOperandRecurrence again. But As we know it is possible that after
SCEV folding, we cannot prove the legality using the SCEVAddRecExpr returned
by getWideRecurrence. Meanwhile if getExtendedOperandRecurrence returns non-null
WideAddRec, we know for sure that it is legal to do widening for current instruction.
So it is better to put getExtendedOperandRecurrence before getWideRecurrence, which
will increase the chance of successful widening.

Differential Revision: https://reviews.llvm.org/D26059


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@286987 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-15 17:34:52 +00:00

128 lines
4.0 KiB
LLVM

; RUN: opt < %s -indvars -S | FileCheck %s
; RUN: opt -lcssa -loop-simplify -S < %s | opt -S -passes='require<targetir>,require<scalar-evolution>,require<domtree>,loop(indvars)'
; Provide legal integer types.
target datalayout = "n8:16:32:64"
target triple = "x86_64-apple-darwin"
; CHECK-LABEL: @loop_0
; CHECK-LABEL: B18:
; Only one phi now.
; CHECK: phi
; CHECK-NOT: phi
; One trunc for the gep.
; CHECK: trunc i64 %indvars.iv to i32
; One trunc for the dummy() call.
; CHECK-LABEL: exit24:
; CHECK: trunc i64 {{.*}}lcssa.wide to i32
define void @loop_0(i32* %a) {
Prologue:
br i1 undef, label %B18, label %B6
B18: ; preds = %B24, %Prologue
%.02 = phi i32 [ 0, %Prologue ], [ %tmp33, %B24 ]
%tmp23 = zext i32 %.02 to i64
%tmp33 = add i32 %.02, 1
%o = getelementptr i32, i32* %a, i32 %.02
%v = load i32, i32* %o
%t = icmp eq i32 %v, 0
br i1 %t, label %exit24, label %B24
B24: ; preds = %B18
%t2 = icmp eq i32 %tmp33, 20
br i1 %t2, label %B6, label %B18
B6: ; preds = %Prologue
ret void
exit24: ; preds = %B18
call void @dummy(i32 %.02)
unreachable
}
define void @loop_1(i32 %lim) {
; CHECK-LABEL: @loop_1(
entry:
%entry.cond = icmp ne i32 %lim, 0
br i1 %entry.cond, label %loop, label %leave
loop:
; CHECK: loop:
; CHECK: %indvars.iv = phi i64 [ 1, %loop.preheader ], [ %indvars.iv.next, %loop ]
; CHECK: %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
; CHECK: [[IV_INC:%[^ ]+]] = add nsw i64 %indvars.iv, -1
; CHECK: call void @dummy.i64(i64 [[IV_INC]])
%iv = phi i32 [ 1, %entry ], [ %iv.inc, %loop ]
%iv.inc = add i32 %iv, 1
%iv.inc.sub = add i32 %iv, -1
%iv.inc.sub.zext = zext i32 %iv.inc.sub to i64
call void @dummy.i64(i64 %iv.inc.sub.zext)
%be.cond = icmp ult i32 %iv.inc, %lim
br i1 %be.cond, label %loop, label %leave
leave:
ret void
}
declare void @dummy(i32)
declare void @dummy.i64(i64)
define void @loop_2(i32 %size, i32 %nsteps, i32 %hsize, i32* %lined, i8 %tmp1) {
; CHECK-LABEL: @loop_2(
entry:
%cmp215 = icmp sgt i32 %size, 1
%tmp0 = bitcast i32* %lined to i8*
br label %for.body
for.body:
%j = phi i32 [ 0, %entry ], [ %inc6, %for.inc ]
%mul = mul nsw i32 %j, %size
%add = add nsw i32 %mul, %hsize
br i1 %cmp215, label %for.body2, label %for.inc
; check that the induction variable of the inner loop has been widened after indvars.
; CHECK: [[INNERLOOPINV:%[^ ]+]] = add nsw i64
; CHECK: for.body2:
; CHECK-NEXT: %indvars.iv = phi i64 [ 1, %for.body2.preheader ], [ %indvars.iv.next, %for.body2 ]
; CHECK-NEXT: [[WIDENED:%[^ ]+]] = add nsw i64 [[INNERLOOPINV]], %indvars.iv
; CHECK-NEXT: %add.ptr = getelementptr inbounds i8, i8* %tmp0, i64 [[WIDENED]]
for.body2:
%k = phi i32 [ %inc, %for.body2 ], [ 1, %for.body ]
%add4 = add nsw i32 %add, %k
%idx.ext = sext i32 %add4 to i64
%add.ptr = getelementptr inbounds i8, i8* %tmp0, i64 %idx.ext
store i8 %tmp1, i8* %add.ptr, align 1
%inc = add nsw i32 %k, 1
%cmp2 = icmp slt i32 %inc, %size
br i1 %cmp2, label %for.body2, label %for.body3
; check that the induction variable of the inner loop has been widened after indvars.
; CHECK: for.body3.preheader:
; CHECK: [[INNERLOOPINV:%[^ ]+]] = zext i32
; CHECK: for.body3:
; CHECK-NEXT: %indvars.iv2 = phi i64 [ 1, %for.body3.preheader ], [ %indvars.iv.next3, %for.body3 ]
; CHECK-NEXT: [[WIDENED:%[^ ]+]] = add nuw nsw i64 [[INNERLOOPINV]], %indvars.iv2
; CHECK-NEXT: %add.ptr2 = getelementptr inbounds i8, i8* %tmp0, i64 [[WIDENED]]
for.body3:
%l = phi i32 [ %inc2, %for.body3 ], [ 1, %for.body2 ]
%add5 = add nuw i32 %add, %l
%idx.ext2 = zext i32 %add5 to i64
%add.ptr2 = getelementptr inbounds i8, i8* %tmp0, i64 %idx.ext2
store i8 %tmp1, i8* %add.ptr2, align 1
%inc2 = add nsw i32 %l, 1
%cmp3 = icmp slt i32 %inc2, %size
br i1 %cmp3, label %for.body3, label %for.inc
for.inc:
%inc6 = add nsw i32 %j, 1
%cmp = icmp slt i32 %inc6, %nsteps
br i1 %cmp, label %for.body, label %for.end.loopexit
for.end.loopexit:
ret void
}