[llvm] r186272 - Teach indvars to generate nsw/nuw flags when widening an induction variable.
Andrew Trick
atrick at apple.com
Sat Jul 13 19:50:08 PDT 2013
Author: atrick
Date: Sat Jul 13 21:50:07 2013
New Revision: 186272
URL: http://llvm.org/viewvc/llvm-project?rev=186272&view=rev
Log:
Teach indvars to generate nsw/nuw flags when widening an induction variable.
Fixes PR16600.
Added:
llvm/trunk/test/Transforms/IndVarSimplify/widen-nsw.ll
Modified:
llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
Modified: llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp?rev=186272&r1=186271&r2=186272&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp Sat Jul 13 21:50:07 2013
@@ -1137,7 +1137,12 @@ SCEVExpander::getAddRecExprPHILiterally(
IVIncInsertPos : Pred->getTerminator();
Builder.SetInsertPoint(InsertPos);
Value *IncV = expandIVInc(PN, StepV, L, ExpandTy, IntTy, useSubtract);
-
+ if (isa<OverflowingBinaryOperator>(IncV)) {
+ if (Normalized->getNoWrapFlags(SCEV::FlagNUW))
+ cast<BinaryOperator>(IncV)->setHasNoUnsignedWrap();
+ if (Normalized->getNoWrapFlags(SCEV::FlagNSW))
+ cast<BinaryOperator>(IncV)->setHasNoSignedWrap();
+ }
PN->addIncoming(IncV, Pred);
}
Added: llvm/trunk/test/Transforms/IndVarSimplify/widen-nsw.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/IndVarSimplify/widen-nsw.ll?rev=186272&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/IndVarSimplify/widen-nsw.ll (added)
+++ llvm/trunk/test/Transforms/IndVarSimplify/widen-nsw.ll Sat Jul 13 21:50:07 2013
@@ -0,0 +1,29 @@
+; RUN: opt < %s -indvars -S | FileCheck %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx"
+
+; CHECK-LABEL: @test1
+; CHECK: %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+define i32 @test1(i32* %a) #0 {
+entry:
+ br label %for.cond
+
+for.cond: ; preds = %for.body, %entry
+ %sum.0 = phi i32 [ 0, %entry ], [ %add, %for.body ]
+ %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+ %cmp = icmp slt i32 %i.0, 1000
+ br i1 %cmp, label %for.body, label %for.end
+
+for.body: ; preds = %for.cond
+ %idxprom = sext i32 %i.0 to i64
+ %arrayidx = getelementptr inbounds i32* %a, i64 %idxprom
+ %0 = load i32* %arrayidx, align 4
+ %add = add nsw i32 %sum.0, %0
+ %inc = add nsw i32 %i.0, 1
+ br label %for.cond
+
+for.end: ; preds = %for.cond
+ ret i32 %sum.0
+}
+
+attributes #0 = { nounwind ssp uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }
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