Assertion failed: (!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet"), function ExpandLegalINT_TO_FP, file lib/CodeGen/Selection DAG/LegalizeDAG.cpp, line 2420.

[pkubaj]

Bugzilla Link	45274
Resolution	FIXED
Resolved on	Apr 01, 2021 08:08
Version	10.0
OS	FreeBSD
Blocks	#44654
Attachments	reproduction files
CC	@adalava,@topperc,@tstellar

Extended Description

FreeBSD head on powerpc64 with LLVM 10 rc4.

Compiling emulators/mednafen port fails, this is a regression from 9.0.1:
Assertion failed: (!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet"), function ExpandLegalINT_TO_FP, file /usr/src/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp, line 2420.
Stack dump:
0. Program arguments: c++ -std=gnu++11 -fsigned-char -DLOCALEDIR="/usr/local/share/locale" -DHAVE_CONFIG_H -I/usr/local/include/SDL2 -I/usr/local/include -D_REENTRANT -D_THREAD_SAFE -I../../include -I../../include -I../../intl -I/usr/local/include -DLIBICONV_PLUG -D_THREAD_SAFE -fno-fast-math -fno-unsafe-math-optimizations -fomit-frame-pointer -fstrict-aliasing -Wall -Wshadow -Wempty-body -Wignored-qualifiers -Wvla -Wvariadic-macros -Wdisabled-optimization -Werror=write-strings -fno-pic -fno-pie -fno-PIC -fno-PIE -fwrapv -fjump-tables
-fexceptions -O2 -pipe -DLIBICONV_PLUG -fstack-protector-strong -fno-strict-aliasing -DLIBICONV_PLUG -MT ers.o -MD -MP -MF .deps/ers.Tpo -c -o ers.o ers.cpp

1.  <eof> parser at end of file
   

2.  Code generation
   

3.  Running pass 'Function Pass Manager' on module 'ers.cpp'.
   

4.  Running pass 'PowerPC DAG->DAG Pattern Instruction Selection' on function '@_ZN14EmuRealSyncher10AddEmuTimeElb'
   

[topperc]

Looks to be related to the -ffp-exception-behavior=strict option

[pkubaj]

Here's a reduced test case:
double a;
long b;
void c() { b / a; }

I also reduced compilation options to:
/usr/bin/c++ -cc1 -triple powerpc64-unknown-freebsd13.0 -emit-obj -ffp-exception-behavior=strict -x c++ main-8d9e47.cpp

[adalava]

It looks like bug #​45237

Also reproduced on LLVM10 and trunk@3e315697ac7. Ommiting -ffp-exception-behavior=strict workarounds it. It's not reproduced on LLVM9 however -ffp-exception-behavior=strict is not available on that version.

[adalava]

Despite being a regression between 9 and 10, marking the release-10.0.1 blocker for you to decide. Thanks!

[tstellar]

Is there a fix for this?

[pkubaj]

Seems to work fine in LLVM 11.0.1.

[tstellar]

mentioned in issue #44654