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[NewGVN] Delete the old store when we find congruent to a load. 

(or non-store, more in general). Fixes PR33086. Caught by the
store verifier.

llvm-svn: 303406
This commit is contained in:
Davide Italiano 2017-05-19 04:06:10 +00:00
parent 977158488e
commit ee49f4943c
2 changed files with 61 additions and 2 deletions
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4
llvm/lib/Transforms/Scalar/NewGVN.cpp
View File

@ -2111,11 +2111,11 @@ void NewGVN::performCongruenceFinding(Instruction *I, const Expression *E) {
// old store expression. In particular, loads do not compare against stored
// value, so they will find old store expressions (and associated class
// mappings) if we leave them in the table.
if (ClassChanged && isa<StoreExpression>(E)) {
if (ClassChanged && isa<StoreInst>(I)) {
auto *OldE = ValueToExpression.lookup(I);
// It could just be that the old class died. We don't want to erase it if we
// just moved classes.
if (OldE && isa<StoreExpression>(OldE) && !OldE->equals(*E))
if (OldE && isa<StoreExpression>(OldE) && *E != *OldE)
ExpressionToClass.erase(OldE);
}
ValueToExpression[I] = E;

59
llvm/test/Transforms/NewGVN/pr33086.ll Normal file
View File

@ -0,0 +1,59 @@
; RUN: opt -newgvn -S %s | FileCheck %s
; REQUIRES: asserts
; CHECK-LABEL: define void @tinkywinky() {
; CHECK: entry:
; CHECK-NEXT: br i1 undef, label %for.cond18, label %for.cond.preheader
; CHECK: for.cond.preheader:
; CHECK-NEXT: br label %for.cond2thread-pre-split
; CHECK: for.cond2thread-pre-split:
; CHECK-NEXT: %conv24 = phi i32 [ 0, %for.cond.preheader ], [ %conv, %for.inc.split ]
; CHECK-NEXT: br label %for.inc.split
; CHECK: for.inc.split:
; CHECK-NEXT: %add = shl nsw i32 %conv24, 16
; CHECK-NEXT: %sext23 = add i32 %add, 65536
; CHECK-NEXT: %conv = ashr exact i32 %sext23, 16
; CHECK-NEXT: %cmp = icmp slt i32 %sext23, 3604480
; CHECK-NEXT: br i1 %cmp, label %for.cond2thread-pre-split, label %l1.loopexit
; CHECK: l1.loopexit:
; CHECK-NEXT: br label %l1
; CHECK: l1:
; CHECK-NEXT: %0 = load i16, i16* null, align 2
; CHECK-NEXT: %g.0.g.0..pr = load i16, i16* null, align 2
; CHECK-NEXT: ret void
; CHECK: for.cond18:
; CHECK-NEXT: br label %l1
; CHECK-NEXT: }
define void @tinkywinky() {
entry:
br i1 undef, label %for.cond18, label %for.cond.preheader
for.cond.preheader:
br label %for.cond2thread-pre-split
for.cond2thread-pre-split:
%conv24 = phi i32 [ 0, %for.cond.preheader ], [ %conv, %for.inc.split ]
br label %for.inc.split
for.inc.split:
%add = shl nsw i32 %conv24, 16
%sext23 = add i32 %add, 65536
%conv = ashr exact i32 %sext23, 16
%cmp = icmp slt i32 %sext23, 3604480
br i1 %cmp, label %for.cond2thread-pre-split, label %l1.loopexit
l1.loopexit:
br label %l1
l1:
%h.0 = phi i16* [ undef, %for.cond18 ], [ null, %l1.loopexit ]
%0 = load i16, i16* %h.0, align 2
store i16 %0, i16* null, align 2
%g.0.g.0..pr = load i16, i16* null, align 2
%tobool15 = icmp eq i16 %g.0.g.0..pr, 0
ret void
for.cond18:
br label %l1
}