Assertion failed: (!IsStrict && "Don't know how to expand for strict nodes."), function ExpandNode, file llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp, line 3638.

[pkubaj]

Bugzilla Link	45237
Resolution	FIXED
Resolved on	Dec 08, 2020 14:07
Version	10.0
OS	FreeBSD
Blocks	#44654
Attachments	reproduction files
CC	@adalava,@tstellar

Extended Description

FreeBSD head on powerpc64, LLVM 10 rc3.

I'm building x11/babl port:
FAILED: babl/base/935b676@@babl_base@sta/model-cmyk.c.o
cc -Ibabl/base/935b676@@babl_base@sta -Ibabl/base -I../babl/base -I. -I../ -Ibabl -I../babl -I/usr/local/include -Xclang -fcolor-diagnostics -pipe -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -O3 -Ofast -fno-unsafe-math-optimizations -Wdeclaration-after-statement -Winit-self -Wmissing-declarations -Wmissing-prototypes -Wold-style-definition -Wpointer-arith -O2 -fstack-protector-strong -isystem /usr/local/include -fno-strict-aliasing -isystem /usr/local/include -fPIC -MD -MQ 'babl/base/935b676@@babl_base@sta/model-cmyk.c.o' -MF 'babl/base/935b676@@babl_base@sta/model-cmyk.c.o.d' -o 'babl/base/935b676@@babl_base@sta/model-cmyk.c.o' -c ../babl/base/model-cmyk.c
Assertion failed: (!IsStrict && "Don't know how to expand for strict nodes."), function ExpandNode, file /usr/src/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp, line 3638.
Stack dump:
0. Program arguments: cc -Ibabl/base/935b676@@babl_base@sta -Ibabl/base -I../babl/base -I. -I../ -Ibabl -I../babl -I/usr/local/include -Xclang -fcolor-diagnostics -pipe -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -O3 -Ofast -fno-unsafe-math-optimizations -Wdeclaration-after-statement -Winit-self -Wmissing-declarations -Wmissing-prototypes -Wold-style-definition -Wpointer-arith -O2 -fstack-protector-strong -isystem /usr/local/include -fno-strict-aliasing -isystem /usr/local/include -fPIC -MD -MQ babl/base/935b676@@babl_base@sta/model-cmyk.c.o -MF babl/base/935b676@@babl_base@sta/model-cmyk.c.o.d -o babl/base/935b676@@babl_base@sta/model-cmyk.c.o -c ../babl/base/model-cmyk.c

1.  <eof> parser at end of file
   

2.  Code generation
   

3.  Running pass 'Function Pass Manager' on module '../babl/base/model-cmyk.c'.
   

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

#​0 0x0000000013bac208 PrintStackTrace /usr/src/contrib/llvm-project/llvm/lib/Support/Unix/Signals.inc:564:13
#​1 0x0000000013ba98d0 RunSignalHandlers /usr/src/contrib/llvm-project/llvm/lib/Support/Signals.cpp:67:5
#​2 0x0000000013baf278 HandleCrash /usr/src/contrib/llvm-project/llvm/lib/Support/CrashRecoveryContext.cpp:75:7
#​3 0x0000000013baf4ec CrashRecoverySignalHandler /usr/src/contrib/llvm-project/llvm/lib/Support/CrashRecoveryContext.cpp:0:51
#​4 0x0000000815732748 handle_signal /usr/src/lib/libthr/thread/thr_sig.c:303:3
cc: error: clang frontend command failed due to signal (use -v to see invocation)
FreeBSD clang version 10.0.0 (git@github.com:llvm/llvm-project.git llvmorg-10.0.0-rc3-1-gc290cb61fdc)
Target: powerpc64-unknown-freebsd13.0
Thread model: posix
InstalledDir: /usr/bin
cc: note: diagnostic msg: PLEASE submit a bug report to https://bugs.freebsd.org/submit/ and include the crash backtrace, preprocessed source, and associated run script.
cc: note: diagnostic msg:

---

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
cc: note: diagnostic msg: /tmp/model-cmyk-32e52d.c
cc: note: diagnostic msg: /tmp/model-cmyk-32e52d.sh
cc: note: diagnostic msg:

---

I'm attaching the files needed for reproduction.

[pkubaj]

This is a regression from 9.0.1.

[pkubaj]

rc4 with the necessary patch backported fixes this issue, thanks!

[pkubaj]

This issue wasn't completely fixed. babl builds on powerpc64 now, but I discovered clang exiting with the same assert on powerpc, while building x11/babl as well.

Reduced test case:
double a;
b() {
if (a)
;
}

Compile with:
/usr/bin/cc -cc1 -triple powerpc-unknown-freebsd13.0 -emit-obj -ffp-exception-behavior=strict model-cmyk-61260b.c

Compiling the same test case for powerpc64 and powerpcspe also makes clang fail on the same assertion.

[adalava]

This issue wasn't completely fixed. babl builds on powerpc64 now, but I
discovered clang exiting with the same assert on powerpc, while building
x11/babl as well.

Reduced test case:
double a;
b() {
if (a)
;
}

Compile with:
/usr/bin/cc -cc1 -triple powerpc-unknown-freebsd13.0 -emit-obj
-ffp-exception-behavior=strict model-cmyk-61260b.c

Compiling the same test case for powerpc64 and powerpcspe also makes clang
fail on the same assertion.

On both LLVM10 and trunk@3e315697ac7 this code compiles fine when parameter "-ffp-exception-behavior=strict" is ommited.

On LLVM9 this parameter seems to now exist, so it compiles fine without it as well.

[adalava]

On LLVM9 this parameter seems to now exist, so it compiles fine without it
as well.

I meant this parameter is not available on LLVM9

[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]

Works with clang version 11.0.0 (git@github.com:llvm/llvm-project.git llvmorg-11.0.0-0-g176249bd673).

[tstellar]

mentioned in issue #44654