llvm-mirror/test/Transforms/JumpThreading/pr22086.ll
David Majnemer 8ed72d8999 ValueTracking: ComputeNumSignBits should tolerate misshapen phi nodes
PHI nodes can have zero operands in the middle of a transform.  It is
expected that utilities in Analysis don't freak out when this happens.

Note that it is considered invalid to allow these misshapen phi nodes to
make it to another pass.

This fixes PR22086.

llvm-svn: 225126
2015-01-04 07:06:53 +00:00

29 lines
640 B
LLVM

; RUN: opt -S -jump-threading < %s | FileCheck %s
; CHECK-LABEL: @f(
; CHECK-LABEL: entry:
; CHECK-NEXT: br label %[[loop:.*]]
; CHECK: [[loop]]:
; CHECK-NEXT: br label %[[loop]]
define void @f() {
entry:
br label %for.cond1
if.end16:
%phi1 = phi i32 [ undef, %for.cond1 ]
%g.3 = phi i32 [ %g.1, %for.cond1 ]
%sext = shl i32 %g.3, 16
%conv20 = ashr exact i32 %sext, 16
%tobool21 = icmp eq i32 %phi1, 0
br i1 %tobool21, label %lor.rhs, label %for.cond1
for.cond1:
%g.1 = phi i32 [ 0, %entry ], [ 0, %lor.rhs ], [ %g.3, %if.end16 ]
br i1 undef, label %lor.rhs, label %if.end16
lor.rhs:
br label %for.cond1
}