llvm-6502/test/Transforms/GVN/rle-nonlocal.ll
Shuxin Yang d93e8a06b2 Resurrect r191017 " GVN proceeds in the presence of dead code" plus a fix to PR17307 & 17308.
The problem of r191017 is that when GVN fabricate a val-number for a dead instruction (in order
to make following expr-PRE happy), it forget to fabricate a leader-table entry for it as well.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191118 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-20 23:12:57 +00:00

26 lines
507 B
LLVM

; RUN: opt < %s -basicaa -gvn -S | FileCheck %s
define i32 @main(i32** %p, i32 %x, i32 %y) {
block1:
%cmp = icmp eq i32 %x, %y
br i1 %cmp , label %block2, label %block3
block2:
%a = load i32** %p
br label %block4
block3:
%b = load i32** %p
br label %block4
block4:
; CHECK-NOT: %existingPHI = phi
; CHECK: %DEAD = phi
%existingPHI = phi i32* [ %a, %block2 ], [ %b, %block3 ]
%DEAD = load i32** %p
%c = load i32* %DEAD
%d = load i32* %existingPHI
%e = add i32 %c, %d
ret i32 %e
}