[PruneEH] Be correct in the face IPO

This fixes one spot I had missed in r265762.  Credit goes to Philip
Reames for spotting this one!

llvm-svn: 283137
This commit is contained in:
Sanjoy Das 2016-10-03 19:35:30 +00:00
parent 31dd377ffc
commit 0359a193a7
2 changed files with 44 additions and 4 deletions

View File

@ -90,10 +90,7 @@ static bool runImpl(CallGraphSCC &SCC, CallGraph &CG) {
if (!F) {
SCCMightUnwind = true;
SCCMightReturn = true;
} else if (F->isDeclaration() || F->isInterposable()) {
// Note: isInterposable (as opposed to hasExactDefinition) is fine above,
// since we're not inferring new attributes here, but only using existing,
// assumed to be correct, function attributes.
} else if (!F->hasExactDefinition()) {
SCCMightUnwind |= !F->doesNotThrow();
SCCMightReturn |= !F->doesNotReturn();
} else {

View File

@ -0,0 +1,43 @@
; RUN: opt -S -prune-eh < %s | FileCheck %s
declare void @may_throw()
; @callee below may be an optimized form of this function, which can
; throw at runtime (see r265762 for more details):
;
; define linkonce_odr void @callee(i32* %ptr) noinline {
; entry:
; %val0 = load atomic i32, i32* %ptr unordered, align 4
; %val1 = load atomic i32, i32* %ptr unordered, align 4
; %cmp = icmp eq i32 %val0, %val1
; br i1 %cmp, label %left, label %right
; left:
; ret void
; right:
; call void @may_throw()
; ret void
; }
define linkonce_odr void @callee(i32* %ptr) noinline {
ret void
}
define i32 @caller(i32* %ptr) personality i32 3 {
; CHECK-LABEL: @caller(
; CHECK: invoke void @callee(i32* %ptr)
; CHECK-NEXT: to label %normal unwind label %unwind
entry:
invoke void @callee(i32* %ptr)
to label %normal unwind label %unwind
normal:
ret i32 1
unwind:
%res = landingpad { i8*, i32 }
cleanup
ret i32 2
}