llvm-6502/test/Transforms/SimplifyCFG/PR16069.ll
Rafael Espindola babae05237 Second part of pr16069
The problem this time seems to be a thinko. We were assuming that in the CFG

A
| \
|  B
| /
C

speculating the basic block B would cause only the phi value for the B->C edge
to be speculated. That is not true, the phi's are semantically in the edges, so
if the A->B->C path is taken, any code needed for A->C is not executed and we
have to consider it too when deciding to speculate B.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183226 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-04 14:11:59 +00:00

29 lines
803 B
LLVM

; RUN: opt < %s -simplifycfg -S | FileCheck %s
@b = extern_weak global i32
define i32 @foo(i1 %y) {
; CHECK: define i32 @foo(i1 %y) {
br i1 %y, label %bb1, label %bb2
bb1:
br label %bb3
bb2:
br label %bb3
bb3:
%cond.i = phi i32 [ 0, %bb1 ], [ srem (i32 1, i32 zext (i1 icmp eq (i32* @b, i32* null) to i32)), %bb2 ]
; CHECK: phi i32 {{.*}} srem (i32 1, i32 zext (i1 icmp eq (i32* @b, i32* null) to i32)), %bb2
ret i32 %cond.i
}
define i32 @foo2(i1 %x) {
; CHECK: define i32 @foo2(i1 %x) {
bb0:
br i1 %x, label %bb1, label %bb2
bb1:
br label %bb2
bb2:
%cond = phi i32 [ 0, %bb1 ], [ srem (i32 1, i32 zext (i1 icmp eq (i32* @b, i32* null) to i32)), %bb0 ]
; CHECK: %cond = phi i32 [ 0, %bb1 ], [ srem (i32 1, i32 zext (i1 icmp eq (i32* @b, i32* null) to i32)), %bb0 ]
ret i32 %cond
}