[llvm] r269426 - [InstCombine] canonicalize* LE/GE vector integer comparisons to LT/GT (PR26701, PR26819)
Silviu Baranga via llvm-commits
llvm-commits at lists.llvm.org
Tue May 17 04:59:02 PDT 2016
Hi Sanjay,
Looks like we have another failure related to this:
https://llvm.org/bugs/show_bug.cgi?id=27786
Could you please have a look?
Cheers,
Silviu
From: llvm-commits [mailto:llvm-commits-bounces at lists.llvm.org] On Behalf Of Sanjay Patel via llvm-commits
Sent: 16 May 2016 16:16
To: James Molloy
Cc: llvm-commits
Subject: Re: [llvm] r269426 - [InstCombine] canonicalize* LE/GE vector integer comparisons to LT/GT (PR26701, PR26819)
Thanks, James. Taking a look now.
On Mon, May 16, 2016 at 8:48 AM, James Molloy <james at jamesmolloy.co.uk<mailto: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<mailto: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 {
_______________________________________________
llvm-commits mailing list
llvm-commits at lists.llvm.org<mailto:llvm-commits at lists.llvm.org>
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20160517/17c54b82/attachment.html>
More information about the llvm-commits
mailing list