f9471b0010
Summary: Select folding in JumpThreading can create a conditional branch on a code patch that did not have one in the original program. This is not a valid transformation in sanitize_memory functions. Note that JumpThreading does select folding in 3 different places. Two of them seem safe - they apply to a select instruction in a BB that ends with an unconditional branch to another BB, which (in turn) ends with a conditional branch or a switch with the same condition. Fixes PR45220. Reviewers: glider, dvyukov, efriedma Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D76332
29 lines
645 B
LLVM
29 lines
645 B
LLVM
; PR45220
|
|
; RUN: opt -S -jump-threading < %s | FileCheck %s
|
|
|
|
declare i1 @NOP()
|
|
|
|
define dso_local i32 @f(i1 %b, i1 %u) sanitize_memory {
|
|
entry:
|
|
br i1 %b, label %if.end, label %if.else
|
|
|
|
if.else:
|
|
%call = call i1 @NOP()
|
|
br label %if.end
|
|
|
|
if.end:
|
|
; Check that both selects in this BB are still in place,
|
|
; and were not replaced with a conditional branch.
|
|
; CHECK: phi
|
|
; CHECK-NEXT: phi
|
|
; CHECK-NEXT: select
|
|
; CHECK-NEXT: select
|
|
; CHECK-NEXT: ret
|
|
%u1 = phi i1 [ true, %if.else ], [ %u, %entry ]
|
|
%v = phi i1 [ %call, %if.else ], [ false, %entry ]
|
|
%s = select i1 %u1, i32 22, i32 0
|
|
%v1 = select i1 %v, i32 %s, i32 42
|
|
ret i32 %v1
|
|
}
|
|
|