[llvm] r269426 - [InstCombine] canonicalize* LE/GE vector integer comparisons to LT/GT (PR26701, PR26819)
Sanjay Patel via llvm-commits
llvm-commits at lists.llvm.org
Mon May 16 08:15:42 PDT 2016
Thanks, James. Taking a look now.
On Mon, May 16, 2016 at 8:48 AM, James Molloy <james at jamesmolloy.co.uk>
wrote:
> Hi Sanjay,
>
> Our internal random builders have found a failing testcase that bisects to
> this commit. Could you please take a look?
>
> To reproduce: opt -instcombine test.ll -disable-output
> opt:
> /work/llvm-test/slave2/continuous/build/llvm/include/llvm/Support/Casting.h:237:
> typename cast_retty<X, Y *>::ret_type llvm::cast(Y *) [X =
> llvm::ConstantInt, Y = llvm::Constant]: Assertion `isa<X>(Val) &&
> "cast<Ty>() argument of incompatible type!"' failed.
>
> The testcase is available at http://llvm.org/pr27756 .
>
> Cheers,
>
> James
>
> On Fri, 13 May 2016 at 16:16 Sanjay Patel via llvm-commits <
> llvm-commits at lists.llvm.org> wrote:
>
>> Author: spatel
>> Date: Fri May 13 10:10:46 2016
>> New Revision: 269426
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=269426&view=rev
>> Log:
>> [InstCombine] canonicalize* LE/GE vector integer comparisons to LT/GT
>> (PR26701, PR26819)
>>
>> *We don't currently handle the edge case constants (min/max values), so
>> it's not a complete
>> canonicalization.
>>
>> To fully solve the motivating bugs, we need to enhance this to recognize
>> a zero vector
>> too because that's a ConstantAggregateZero which is a ConstantData, not a
>> ConstantVector
>> or a ConstantDataVector.
>>
>> Differential Revision: http://reviews.llvm.org/D17859
>>
>>
>>
>> Added:
>> llvm/trunk/test/Transforms/InstCombine/icmp-vec.ll
>> Modified:
>> llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
>> llvm/trunk/test/Transforms/LoopVectorize/if-conversion.ll
>>
>> Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp?rev=269426&r1=269425&r2=269426&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
>> (original)
>> +++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp Fri May
>> 13 10:10:46 2016
>> @@ -3125,11 +3125,64 @@ static ICmpInst *canonicalizeCmpWithCons
>> assert(!Op1C->isMinValue(true)); // A >=s MIN -> TRUE
>> return new ICmpInst(ICmpInst::ICMP_SGT, Op0, Builder.getInt(Op1Val
>> - 1));
>> default:
>> - break;
>> + return nullptr;
>> }
>> }
>>
>> - // TODO: Handle vectors.
>> + // The usual vector types are ConstantDataVector. Exotic vector types
>> are
>> + // ConstantVector. They both derive from Constant.
>> + if (isa<ConstantDataVector>(Op1) || isa<ConstantVector>(Op1)) {
>> + Constant *Op1C = cast<Constant>(Op1);
>> + Type *Op1Type = Op1->getType();
>> + unsigned NumElts = Op1Type->getVectorNumElements();
>> +
>> + // Set the new comparison predicate and splat a vector of 1 or -1 to
>> + // increment or decrement the vector constants. But first, check
>> that no
>> + // elements of the constant vector would overflow/underflow when we
>> + // increment/decrement the constants.
>> + //
>> + // TODO? If the edge cases for vectors were guaranteed to be handled
>> as they
>> + // are for scalar, we could remove the min/max checks here. However,
>> to do
>> + // that, we would have to use insertelement/shufflevector to replace
>> edge
>> + // values.
>> +
>> + CmpInst::Predicate NewPred;
>> + Constant *OneOrNegOne = nullptr;
>> + switch (I.getPredicate()) {
>> + case ICmpInst::ICMP_ULE:
>> + for (unsigned i = 0; i != NumElts; ++i)
>> + if
>> (cast<ConstantInt>(Op1C->getAggregateElement(i))->isMaxValue(false))
>> + return nullptr;
>> + NewPred = ICmpInst::ICMP_ULT;
>> + OneOrNegOne = ConstantInt::get(Op1Type, 1);
>> + break;
>> + case ICmpInst::ICMP_SLE:
>> + for (unsigned i = 0; i != NumElts; ++i)
>> + if
>> (cast<ConstantInt>(Op1C->getAggregateElement(i))->isMaxValue(true))
>> + return nullptr;
>> + NewPred = ICmpInst::ICMP_SLT;
>> + OneOrNegOne = ConstantInt::get(Op1Type, 1);
>> + break;
>> + case ICmpInst::ICMP_UGE:
>> + for (unsigned i = 0; i != NumElts; ++i)
>> + if
>> (cast<ConstantInt>(Op1C->getAggregateElement(i))->isMinValue(false))
>> + return nullptr;
>> + NewPred = ICmpInst::ICMP_UGT;
>> + OneOrNegOne = ConstantInt::get(Op1Type, -1);
>> + break;
>> + case ICmpInst::ICMP_SGE:
>> + for (unsigned i = 0; i != NumElts; ++i)
>> + if
>> (cast<ConstantInt>(Op1C->getAggregateElement(i))->isMinValue(true))
>> + return nullptr;
>> + NewPred = ICmpInst::ICMP_SGT;
>> + OneOrNegOne = ConstantInt::get(Op1Type, -1);
>> + break;
>> + default:
>> + return nullptr;
>> + }
>> +
>> + return new ICmpInst(NewPred, Op0, ConstantExpr::getAdd(Op1C,
>> OneOrNegOne));
>> + }
>>
>> return nullptr;
>> }
>>
>> Added: llvm/trunk/test/Transforms/InstCombine/icmp-vec.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/icmp-vec.ll?rev=269426&view=auto
>>
>> ==============================================================================
>> --- llvm/trunk/test/Transforms/InstCombine/icmp-vec.ll (added)
>> +++ llvm/trunk/test/Transforms/InstCombine/icmp-vec.ll Fri May 13
>> 10:10:46 2016
>> @@ -0,0 +1,124 @@
>> +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
>> +; RUN: opt < %s -instcombine -S | FileCheck %s
>> +
>> +; Canonicalize vector ge/le comparisons with constants to gt/lt.
>> +
>> +; Normal types are ConstantDataVectors. Test the constant values
>> adjacent to the
>> +; min/max values that we're not allowed to transform.
>> +
>> +define <2 x i1> @sge(<2 x i8> %x) {
>> +; CHECK-LABEL: @sge(
>> +; CHECK-NEXT: [[CMP:%.*]] = icmp sgt <2 x i8> %x, <i8 -128, i8 126>
>> +; CHECK-NEXT: ret <2 x i1> [[CMP]]
>> +;
>> + %cmp = icmp sge <2 x i8> %x, <i8 -127, i8 -129>
>> + ret <2 x i1> %cmp
>> +}
>> +
>> +define <2 x i1> @uge(<2 x i8> %x) {
>> +; CHECK-LABEL: @uge(
>> +; CHECK-NEXT: [[CMP:%.*]] = icmp ugt <2 x i8> %x, <i8 -2, i8 0>
>> +; CHECK-NEXT: ret <2 x i1> [[CMP]]
>> +;
>> + %cmp = icmp uge <2 x i8> %x, <i8 -1, i8 1>
>> + ret <2 x i1> %cmp
>> +}
>> +
>> +define <2 x i1> @sle(<2 x i8> %x) {
>> +; CHECK-LABEL: @sle(
>> +; CHECK-NEXT: [[CMP:%.*]] = icmp slt <2 x i8> %x, <i8 127, i8 -127>
>> +; CHECK-NEXT: ret <2 x i1> [[CMP]]
>> +;
>> + %cmp = icmp sle <2 x i8> %x, <i8 126, i8 128>
>> + ret <2 x i1> %cmp
>> +}
>> +
>> +define <2 x i1> @ule(<2 x i8> %x) {
>> +; CHECK-LABEL: @ule(
>> +; CHECK-NEXT: [[CMP:%.*]] = icmp ult <2 x i8> %x, <i8 -1, i8 1>
>> +; CHECK-NEXT: ret <2 x i1> [[CMP]]
>> +;
>> + %cmp = icmp ule <2 x i8> %x, <i8 254, i8 0>
>> + ret <2 x i1> %cmp
>> +}
>> +
>> +; Weird types are ConstantVectors, not ConstantDataVectors. For an i3
>> type:
>> +; Signed min = -4
>> +; Unsigned min = 0
>> +; Signed max = 3
>> +; Unsigned max = 7
>> +
>> +define <3 x i1> @sge_weird(<3 x i3> %x) {
>> +; CHECK-LABEL: @sge_weird(
>> +; CHECK-NEXT: [[CMP:%.*]] = icmp sgt <3 x i3> %x, <i3 -4, i3 2, i3 -1>
>> +; CHECK-NEXT: ret <3 x i1> [[CMP]]
>> +;
>> + %cmp = icmp sge <3 x i3> %x, <i3 -3, i3 -5, i3 0>
>> + ret <3 x i1> %cmp
>> +}
>> +
>> +define <3 x i1> @uge_weird(<3 x i3> %x) {
>> +; CHECK-LABEL: @uge_weird(
>> +; CHECK-NEXT: [[CMP:%.*]] = icmp ugt <3 x i3> %x, <i3 -2, i3 0, i3 1>
>> +; CHECK-NEXT: ret <3 x i1> [[CMP]]
>> +;
>> + %cmp = icmp uge <3 x i3> %x, <i3 -1, i3 1, i3 2>
>> + ret <3 x i1> %cmp
>> +}
>> +
>> +define <3 x i1> @sle_weird(<3 x i3> %x) {
>> +; CHECK-LABEL: @sle_weird(
>> +; CHECK-NEXT: [[CMP:%.*]] = icmp slt <3 x i3> %x, <i3 3, i3 -3, i3 1>
>> +; CHECK-NEXT: ret <3 x i1> [[CMP]]
>> +;
>> + %cmp = icmp sle <3 x i3> %x, <i3 2, i3 4, i3 0>
>> + ret <3 x i1> %cmp
>> +}
>> +
>> +define <3 x i1> @ule_weird(<3 x i3> %x) {
>> +; CHECK-LABEL: @ule_weird(
>> +; CHECK-NEXT: [[CMP:%.*]] = icmp ult <3 x i3> %x, <i3 -1, i3 1, i3 2>
>> +; CHECK-NEXT: ret <3 x i1> [[CMP]]
>> +;
>> + %cmp = icmp ule <3 x i3> %x, <i3 6, i3 0, i3 1>
>> + ret <3 x i1> %cmp
>> +}
>> +
>> +; We can't do the transform if any constants are already at the limits.
>> +
>> +define <2 x i1> @sge_min(<2 x i3> %x) {
>> +; CHECK-LABEL: @sge_min(
>> +; CHECK-NEXT: [[CMP:%.*]] = icmp sge <2 x i3> %x, <i3 -4, i3 1>
>> +; CHECK-NEXT: ret <2 x i1> [[CMP]]
>> +;
>> + %cmp = icmp sge <2 x i3> %x, <i3 -4, i3 1>
>> + ret <2 x i1> %cmp
>> +}
>> +
>> +define <2 x i1> @uge_min(<2 x i3> %x) {
>> +; CHECK-LABEL: @uge_min(
>> +; CHECK-NEXT: [[CMP:%.*]] = icmp uge <2 x i3> %x, <i3 1, i3 0>
>> +; CHECK-NEXT: ret <2 x i1> [[CMP]]
>> +;
>> + %cmp = icmp uge <2 x i3> %x, <i3 1, i3 0>
>> + ret <2 x i1> %cmp
>> +}
>> +
>> +define <2 x i1> @sle_max(<2 x i3> %x) {
>> +; CHECK-LABEL: @sle_max(
>> +; CHECK-NEXT: [[CMP:%.*]] = icmp sle <2 x i3> %x, <i3 1, i3 3>
>> +; CHECK-NEXT: ret <2 x i1> [[CMP]]
>> +;
>> + %cmp = icmp sle <2 x i3> %x, <i3 1, i3 3>
>> + ret <2 x i1> %cmp
>> +}
>> +
>> +define <2 x i1> @ule_max(<2 x i3> %x) {
>> +; CHECK-LABEL: @ule_max(
>> +; CHECK-NEXT: [[CMP:%.*]] = icmp ule <2 x i3> %x, <i3 -1, i3 1>
>> +; CHECK-NEXT: ret <2 x i1> [[CMP]]
>> +;
>> + %cmp = icmp ule <2 x i3> %x, <i3 7, i3 1>
>> + ret <2 x i1> %cmp
>> +}
>> +
>>
>> Modified: llvm/trunk/test/Transforms/LoopVectorize/if-conversion.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopVectorize/if-conversion.ll?rev=269426&r1=269425&r2=269426&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/test/Transforms/LoopVectorize/if-conversion.ll (original)
>> +++ llvm/trunk/test/Transforms/LoopVectorize/if-conversion.ll Fri May 13
>> 10:10:46 2016
>> @@ -73,7 +73,7 @@ for.end:
>> ;CHECK-LABEL: @reduction_func(
>> ;CHECK: load <4 x i32>
>> ;CHECK: add <4 x i32>
>> -;CHECK: icmp sle <4 x i32>
>> +;CHECK: icmp slt <4 x i32>
>> ;CHECK: select <4 x i1>
>> ;CHECK: ret i32
>> define i32 @reduction_func(i32* nocapture %A, i32 %n) nounwind uwtable
>> readonly ssp {
>>
>>
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>
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