maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

SCEV: Don't assert about non-SCEV-able value in isSCEVExprNeverPoison() (PR28932) 

Differential Revision: https://reviews.llvm.org/D23594

llvm-svn: 278999
This commit is contained in:
Hans Wennborg 2016-08-17 22:50:18 +00:00
parent e787763275
commit 3879035e66
2 changed files with 53 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
llvm/lib/Analysis/ScalarEvolution.cpp
View File

@ -4866,6 +4866,10 @@ bool ScalarEvolution::isSCEVExprNeverPoison(const Instruction *I) {
// from different loops, so that we know which loop to prove that I is
// executed in.
for (unsigned OpIndex = 0; OpIndex < I->getNumOperands(); ++OpIndex) {
// I could be an extractvalue from a call to an overflow intrinsic.
// TODO: We can do better here in some cases.
if (!isSCEVable(I->getOperand(OpIndex)->getType()))
return false;
const SCEV *Op = getSCEV(I->getOperand(OpIndex));
if (auto *AddRec = dyn_cast<SCEVAddRecExpr>(Op)) {
bool AllOtherOpsLoopInvariant = true;

49
llvm/test/Analysis/ScalarEvolution/flags-from-poison.ll
View File

@ -688,3 +688,52 @@ outer.be:
exit:
ret void
}
; PR28932: Don't assert on non-SCEV-able value %2.
%struct.anon = type { i8* }
@a = common global %struct.anon* null, align 8
@b = common global i32 0, align 4
declare { i32, i1 } @llvm.ssub.with.overflow.i32(i32, i32)
declare void @llvm.trap()
define i32 @pr28932() {
entry:
%.pre = load %struct.anon*, %struct.anon** @a, align 8
%.pre7 = load i32, i32* @b, align 4
br label %for.cond
for.cond: ; preds = %cont6, %entry
%0 = phi i32 [ %3, %cont6 ], [ %.pre7, %entry ]
%1 = phi %struct.anon* [ %.ph, %cont6 ], [ %.pre, %entry ]
%tobool = icmp eq %struct.anon* %1, null
%2 = tail call { i32, i1 } @llvm.ssub.with.overflow.i32(i32 %0, i32 1)
%3 = extractvalue { i32, i1 } %2, 0
%4 = extractvalue { i32, i1 } %2, 1
%idxprom = sext i32 %3 to i64
%5 = getelementptr inbounds %struct.anon, %struct.anon* %1, i64 0, i32 0
%6 = load i8*, i8** %5, align 8
%7 = getelementptr inbounds i8, i8* %6, i64 %idxprom
%8 = load i8, i8* %7, align 1
br i1 %tobool, label %if.else, label %if.then
if.then: ; preds = %for.cond
br i1 %4, label %trap, label %cont6
trap: ; preds = %if.else, %if.then
tail call void @llvm.trap()
unreachable
if.else: ; preds = %for.cond
br i1 %4, label %trap, label %cont1
cont1: ; preds = %if.else
%conv5 = sext i8 %8 to i64
%9 = inttoptr i64 %conv5 to %struct.anon*
store %struct.anon* %9, %struct.anon** @a, align 8
br label %cont6
cont6: ; preds = %cont1, %if.then
%.ph = phi %struct.anon* [ %9, %cont1 ], [ %1, %if.then ]
store i32 %3, i32* @b, align 4
br label %for.cond
}