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[InstCombine] Fix constant-folding of overflowing arithmetic ops on vectors 

Feeding vector values to `InstCombiner::OptimizeOverflowCheck` produces a scalar boolean flag if it proves the overflow check can be eliminated.
This causes `InstCombiner::CreateOverflowTuple` to crash as it correctly expects a vector of i1 values instead.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D89628
This commit is contained in:
LemonBoy 2020-11-09 14:39:34 +03:00 committed by Roman Lebedev
parent f4f256fb7b
commit 42732d33cc
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GPG Key ID: 083C3EBB4A1689E0
2 changed files with 166 additions and 3 deletions
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10
llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
View File

@ -4587,9 +4587,13 @@ bool InstCombinerImpl::OptimizeOverflowCheck(Instruction::BinaryOps BinaryOp,
// compare.
Builder.SetInsertPoint(&OrigI);
Type *OverflowTy = Type::getInt1Ty(LHS->getContext());
if (auto *LHSTy = dyn_cast<VectorType>(LHS->getType()))
OverflowTy = VectorType::get(OverflowTy, LHSTy->getElementCount());
if (isNeutralValue(BinaryOp, RHS)) {
Result = LHS;
Overflow = Builder.getFalse();
Overflow = ConstantInt::getFalse(OverflowTy);
return true;
}
@ -4600,12 +4604,12 @@ bool InstCombinerImpl::OptimizeOverflowCheck(Instruction::BinaryOps BinaryOp,
case OverflowResult::AlwaysOverflowsHigh:
Result = Builder.CreateBinOp(BinaryOp, LHS, RHS);
Result->takeName(&OrigI);
Overflow = Builder.getTrue();
Overflow = ConstantInt::getTrue(OverflowTy);
return true;
case OverflowResult::NeverOverflows:
Result = Builder.CreateBinOp(BinaryOp, LHS, RHS);
Result->takeName(&OrigI);
Overflow = Builder.getFalse();
Overflow = ConstantInt::getFalse(OverflowTy);
if (auto *Inst = dyn_cast<Instruction>(Result)) {
if (IsSigned)
Inst->setHasNoSignedWrap();

159
llvm/test/Transforms/InstCombine/with_overflow.ll
View File

@ -597,3 +597,162 @@ define { i8, i1 } @smul_always_overflow(i8 %x) nounwind {
%a = call { i8, i1 } @llvm.smul.with.overflow.i8(i8 %y, i8 2)
ret { i8, i1 } %a
}
declare { <4 x i8>, <4 x i1> } @llvm.sadd.with.overflow.v4i8(<4 x i8>, <4 x i8>)
declare { <4 x i8>, <4 x i1> } @llvm.uadd.with.overflow.v4i8(<4 x i8>, <4 x i8>)
declare { <4 x i8>, <4 x i1> } @llvm.ssub.with.overflow.v4i8(<4 x i8>, <4 x i8>)
declare { <4 x i8>, <4 x i1> } @llvm.usub.with.overflow.v4i8(<4 x i8>, <4 x i8>)
declare { <4 x i8>, <4 x i1> } @llvm.smul.with.overflow.v4i8(<4 x i8>, <4 x i8>)
declare { <4 x i8>, <4 x i1> } @llvm.umul.with.overflow.v4i8(<4 x i8>, <4 x i8>)
; Always overflow
define { <4 x i8>, <4 x i1> } @always_sadd_const_vector() nounwind {
; CHECK-LABEL: @always_sadd_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 -128, i8 -128, i8 -128, i8 -128>, <4 x i1> <i1 true, i1 true, i1 true, i1 true> }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.sadd.with.overflow.v4i8(<4 x i8> <i8 127, i8 127, i8 127, i8 127>, <4 x i8> <i8 1, i8 1, i8 1, i8 1>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @always_uadd_const_vector() nounwind {
; CHECK-LABEL: @always_uadd_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> zeroinitializer, <4 x i1> <i1 true, i1 true, i1 true, i1 true> }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.uadd.with.overflow.v4i8(<4 x i8> <i8 255, i8 255, i8 255, i8 255>, <4 x i8> <i8 1, i8 1, i8 1, i8 1>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @always_ssub_const_vector() nounwind {
; CHECK-LABEL: @always_ssub_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 127, i8 127, i8 127, i8 127>, <4 x i1> <i1 true, i1 true, i1 true, i1 true> }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.ssub.with.overflow.v4i8(<4 x i8> <i8 -128, i8 -128, i8 -128, i8 -128>, <4 x i8> <i8 1, i8 1, i8 1, i8 1>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @always_usub_const_vector() nounwind {
; CHECK-LABEL: @always_usub_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 -1, i8 -1, i8 -1, i8 -1>, <4 x i1> <i1 true, i1 true, i1 true, i1 true> }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.usub.with.overflow.v4i8(<4 x i8> <i8 0, i8 0, i8 0, i8 0>, <4 x i8> <i8 1, i8 1, i8 1, i8 1>)
ret { <4 x i8>, <4 x i1> } %x
}
; NOTE: LLVM doesn't (yet) detect the multiplication always results in a overflow
define { <4 x i8>, <4 x i1> } @always_smul_const_vector() nounwind {
; CHECK-LABEL: @always_smul_const_vector(
; CHECK-NEXT: [[X:%.*]] = call { <4 x i8>, <4 x i1> } @llvm.smul.with.overflow.v4i8(<4 x i8> <i8 127, i8 127, i8 127, i8 127>, <4 x i8> <i8 3, i8 3, i8 3, i8 3>)
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } [[X]]
;
%x = call { <4 x i8>, <4 x i1> } @llvm.smul.with.overflow.v4i8(<4 x i8> <i8 127, i8 127, i8 127, i8 127>, <4 x i8> <i8 3, i8 3, i8 3, i8 3>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @always_umul_const_vector() nounwind {
; CHECK-LABEL: @always_umul_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 -3, i8 -3, i8 -3, i8 -3>, <4 x i1> <i1 true, i1 true, i1 true, i1 true> }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.umul.with.overflow.v4i8(<4 x i8> <i8 255, i8 255, i8 255, i8 255>, <4 x i8> <i8 3, i8 3, i8 3, i8 3>)
ret { <4 x i8>, <4 x i1> } %x
}
; Never overflow
define { <4 x i8>, <4 x i1> } @never_sadd_const_vector() nounwind {
; CHECK-LABEL: @never_sadd_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 -50, i8 -10, i8 0, i8 60>, <4 x i1> zeroinitializer }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.sadd.with.overflow.v4i8(<4 x i8> <i8 -10, i8 -20, i8 30, i8 40>, <4 x i8> <i8 -40, i8 10, i8 -30, i8 20>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @never_uadd_const_vector() nounwind {
; CHECK-LABEL: @never_uadd_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 32, i8 64, i8 96, i8 48>, <4 x i1> zeroinitializer }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.uadd.with.overflow.v4i8(<4 x i8> <i8 0, i8 32, i8 64, i8 16>, <4 x i8> <i8 32, i8 32, i8 32, i8 32>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @never_ssub_const_vector() nounwind {
; CHECK-LABEL: @never_ssub_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 0, i8 10, i8 20, i8 30>, <4 x i1> zeroinitializer }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.ssub.with.overflow.v4i8(<4 x i8> <i8 -10, i8 -10, i8 -10, i8 -10>, <4 x i8> <i8 -10, i8 -20, i8 -30, i8 -40>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @never_usub_const_vector() nounwind {
; CHECK-LABEL: @never_usub_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 127, i8 -1, i8 0, i8 -2>, <4 x i1> zeroinitializer }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.usub.with.overflow.v4i8(<4 x i8> <i8 255, i8 255, i8 255, i8 255>, <4 x i8> <i8 128, i8 0, i8 255, i8 1>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @never_smul_const_vector() nounwind {
; CHECK-LABEL: @never_smul_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 -54, i8 -18, i8 -60, i8 -90>, <4 x i1> zeroinitializer }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.smul.with.overflow.v4i8(<4 x i8> <i8 -6, i8 -6, i8 -6, i8 -6>, <4 x i8> <i8 9, i8 3, i8 10, i8 15>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @never_umul_const_vector() nounwind {
; CHECK-LABEL: @never_umul_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 -31, i8 120, i8 60, i8 30>, <4 x i1> zeroinitializer }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.umul.with.overflow.v4i8(<4 x i8> <i8 15, i8 15, i8 15, i8 15>, <4 x i8> <i8 15, i8 8, i8 4, i8 2>)
ret { <4 x i8>, <4 x i1> } %x
}
; Neutral value
define { <4 x i8>, <4 x i1> } @neutral_sadd_const_vector() nounwind {
; CHECK-LABEL: @neutral_sadd_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 1, i8 2, i8 3, i8 4>, <4 x i1> zeroinitializer }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.sadd.with.overflow.v4i8(<4 x i8> <i8 1, i8 2, i8 3, i8 4>, <4 x i8> <i8 0, i8 0, i8 0, i8 0>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @neutral_uadd_const_vector() nounwind {
; CHECK-LABEL: @neutral_uadd_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 1, i8 2, i8 3, i8 4>, <4 x i1> zeroinitializer }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.uadd.with.overflow.v4i8(<4 x i8> <i8 1, i8 2, i8 3, i8 4>, <4 x i8> <i8 0, i8 0, i8 0, i8 0>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @neutral_ssub_const_vector() nounwind {
; CHECK-LABEL: @neutral_ssub_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 1, i8 2, i8 3, i8 4>, <4 x i1> zeroinitializer }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.ssub.with.overflow.v4i8(<4 x i8> <i8 1, i8 2, i8 3, i8 4>, <4 x i8> <i8 0, i8 0, i8 0, i8 0>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @neutral_usub_const_vector() nounwind {
; CHECK-LABEL: @neutral_usub_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 1, i8 2, i8 3, i8 4>, <4 x i1> zeroinitializer }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.usub.with.overflow.v4i8(<4 x i8> <i8 1, i8 2, i8 3, i8 4>, <4 x i8> <i8 0, i8 0, i8 0, i8 0>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @neutral_smul_const_vector() nounwind {
; CHECK-LABEL: @neutral_smul_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 1, i8 2, i8 3, i8 4>, <4 x i1> zeroinitializer }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.smul.with.overflow.v4i8(<4 x i8> <i8 1, i8 2, i8 3, i8 4>, <4 x i8> <i8 1, i8 1, i8 1, i8 1>)
ret { <4 x i8>, <4 x i1> } %x
}
define { <4 x i8>, <4 x i1> } @neutral_umul_const_vector() nounwind {
; CHECK-LABEL: @neutral_umul_const_vector(
; CHECK-NEXT: ret { <4 x i8>, <4 x i1> } { <4 x i8> <i8 1, i8 2, i8 3, i8 4>, <4 x i1> zeroinitializer }
;
%x = call { <4 x i8>, <4 x i1> } @llvm.umul.with.overflow.v4i8(<4 x i8> <i8 1, i8 2, i8 3, i8 4>, <4 x i8> <i8 1, i8 1, i8 1, i8 1>)
ret { <4 x i8>, <4 x i1> } %x
}