[X86] X86FlagsCopyLowering - Unlowered EFLAGS copy!


Bugzilla Link	PR43189
Status	NEW
Importance	P enhancement
Reported by	Simon Pilgrim (llvm-dev@redking.me.uk)
Reported on	2019-09-01 06:56:19 -0700
Last modified on	2019-09-01 09:55:49 -0700
Version	trunk
Hardware	PC Windows NT
CC	chandlerc@gmail.com, craig.topper@gmail.com, llvm-bugs@lists.llvm.org, llvm-dev@redking.me.uk, spatel+llvm@rotateright.com
Fixed by commit(s)
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Reduced from https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=16605

define void @ossfuzz16605() {
entry:
  %C33 = fcmp true float 0x36A0000000000000, 0x36A0000000000000
  %B43 = or i1 %C33, true
  br i1 %B43, label %bb2, label %bb8

bb8:                                              ; preds = %bb8, %bb7
  %C19 = icmp sgt i128 undef, 18446744073709551616
  %G21 = getelementptr i128, i128* null, i1 %C19
  store i128* %G21, i128** undef
  br i1 %C19, label %bb8, label %bb2

bb2:                                              ; preds = %bb8
  unreachable
}

llc -mtriple=x86_64--

Unlowered EFLAGS copy!
UNREACHABLE executed at C:\LLVM\llvm-
project\llvm\lib\Target\X86\X86FlagsCopyLowering.cpp:707!
Stack dump:
0.      Program arguments: C:\LLVM\build\Debug\bin\llc.exe -mtriple=x86_64-- -
mcpu=btver2 -o bar.s fuzz.ll
1.      Running pass 'Function Pass Manager' on module 'fuzz.ll'.
2.      Running pass 'X86 EFLAGS copy lowering' on function '@ossfuzz16605'

Quuxplusone / LLVMBugzillaTest

[X86] X86FlagsCopyLowering - Unlowered EFLAGS copy! #42159