Make sure we use the right insertion point when instcombine replaces a PHI with another instruction. (Specifically, don't insert an arbitrary instruction before a PHI.) Fixes PR11275.

llvm-svn: 143437
This commit is contained in:
Eli Friedman 2011-11-01 04:49:29 +00:00
parent 038abbd863
commit 676558ae92
2 changed files with 29 additions and 3 deletions

View File

@ -2028,9 +2028,10 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) {
BasicBlock *InstParent = I->getParent();
BasicBlock::iterator InsertPos = I;
if (!isa<PHINode>(Result)) // If combining a PHI, don't insert
while (isa<PHINode>(InsertPos)) // middle of a block of PHIs.
++InsertPos;
// If we replace a PHI with something that isn't a PHI, fix up the
// insertion point.
if (!isa<PHINode>(Result) && isa<PHINode>(InsertPos))
InsertPos = InstParent->getFirstInsertionPt();
InstParent->getInstList().insert(InsertPos, Result);

View File

@ -374,3 +374,28 @@ for.inc: ; preds = %for.cond
return: ; No predecessors!
ret void
}
; PR11275
declare void @test18b() noreturn
declare void @test18foo(double**)
declare void @test18a() noreturn
define fastcc void @test18x(i8* %t0, i1 %b) uwtable align 2 {
entry:
br i1 %b, label %e1, label %e2
e1:
%t2 = bitcast i8* %t0 to double**
invoke void @test18b() noreturn
to label %u unwind label %lpad
e2:
%t4 = bitcast i8* %t0 to double**
invoke void @test18a() noreturn
to label %u unwind label %lpad
lpad:
%t5 = phi double** [ %t2, %e1 ], [ %t4, %e2 ]
%lpad.nonloopexit262 = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
cleanup
call void @test18foo(double** %t5)
unreachable
u:
unreachable
}