Assertion failed: ((CGF.CurFuncDecl == nullptr || CGF.Builder.getIsFPConstrained() || isa<CXXConstructorDecl>(CGF.CurFuncDecl) || isa<CXXDestructorDecl>(CGF.CurFuncDecl) || (NewExceptionBehavior == llvm::fp::ebIgnore && NewRoundingBehavior == llvm::RoundingMode::NearestTiesToEven)) && "FPConstrained should be enabled on entire function"), function ConstructorHelper, file /usr/src/contrib/llvm-project/clang/lib/CodeGen/CodeGenFunction.cpp, line 165. #63542

pkubaj · 2023-06-27T10:14:56Z

FreeBSD 14.0-CURRENT
LLVM 16.0.6
powerpc64le, powerpc64, powerpc

Reproducer:

template <class Compare> void stable_sort(int last, Compare) {
  stable_sort(last, int());
}
#pragma STDC FENV_ACCESS ON
struct cluster_result {
  int operator[](int);
};
template <int> void generate_SciPy_dendrogram() {
  cluster_result Z2;
  int trans_tmp_1(0);
  int trans_tmp_2 = Z2[1];
  stable_sort(trans_tmp_1, trans_tmp_2);
}
void linkage_wrap() { generate_SciPy_dendrogram<false>; }

Build with:

/usr/bin/c++ -cc1 -triple powerpc-unknown-freebsd14.0 -emit-obj fastcluster_python-684654.cpp

Output:

Assertion failed: ((CGF.CurFuncDecl == nullptr || CGF.Builder.getIsFPConstrained() || isa<CXXConstructorDecl>(CGF.CurFuncDecl) || isa<CXXDestructorDecl>(CGF.CurFuncDecl) || (NewExceptionBehavior == llvm::fp::ebIgnore && NewRoundingBehavior == llvm::RoundingMode::NearestTiesToEven)) && "FPConstrained should be enabled on entire function"), function ConstructorHelper, file /usr/src/contrib/llvm-project/clang/lib/CodeGen/CodeGenFunction.cpp, line 165.

VoxSciurorum · 2023-06-27T13:15:31Z

I confirmed this behavior with the system compiler on FreeBSD 14.0-CURRENT on amd64 and aarch64 as well. The ports build of llvm16 does not crash, despite being based on a very similar version of llvm.

pkubaj · 2023-06-27T13:36:14Z

LLVM in ports has assertions disabled, which is probably the reason.

VoxSciurorum · 2023-06-27T13:52:17Z

LLVM in ports has assertions disabled, which is probably the reason.

I think you are right about that. I also reproduced the crash on amd64 Linux using a build with assertions enabled.

DimitryAndric · 2023-06-28T18:49:47Z

This regressed with 65cf77d by @spavloff (cc @rjmccall).

This reverts commit 98390cc. It caused issue #63542.

spavloff · 2023-07-05T07:55:34Z

The reproducer provided here is not related to 65cf77d, because it causes compiler crash with that commit reverted.

The problem reported here is fixed by the patch https://reviews.llvm.org/D154359.

This is recommit of 98390cc, reverted in 82a3969, because it caused #63542. Although the problem described in the issue is independent of the reverted patch, fail of PCH/late-parsed-instantiations.cpp indeed obseved on PowerPC and is likely to be caused by wrong serialization of `LateParsedTemplate` objects. In this patch the serialization is fixed. Original commit message is below. Previously function template instantiations occurred with FP options that were in effect at the end of translation unit. It was a problem for late template parsing as these FP options were used as attributes of AST nodes and may result in crash. To fix it FP options are set to the state of the point of template definition. Differential Revision: https://reviews.llvm.org/D143241

llvmbot · 2023-07-13T05:00:59Z

@llvm/issue-subscribers-clang-frontend

pkubaj · 2023-07-13T12:20:06Z

Would it be possible to merge it to 16?

pkubaj · 2023-07-13T12:35:01Z

@DimitryAndric
Also, a backport to FreeBSD would be well appreciated :)

[clang] Reset FP options before template instantiation AST nodes that may depend on FP options keep them as a difference relative to the options outside the AST node. At the moment of instantiation the FP options may be different from the default values, defined by command-line option. In such case FP attributes would have unexpected values. For example, the code: template <class C> void func_01(int last, C) { func_01(last, int()); } void func_02() { func_01(0, 1); } #pragma STDC FENV_ACCESS ON caused compiler crash, because template instantiation takes place at the end of translation unit, where pragma STDC FENV_ACCESS is in effect. As a result, code in the template instantiation would use constrained intrinsics while the function does not have StrictFP attribute. To solve this problem, FP attributes in Sema must be set to default values, defined by command line options. This change resolves llvm/llvm-project#63542. Differential Revision: https://reviews.llvm.org/D154359 Requested by: pkubaj PR: 265755, 265758 MFC after: 1 month

DimitryAndric · 2023-07-13T19:11:29Z

I think clang 17 is going to be branched soon, so 16 is a bit "old" already... In any case I have merged it into FreeBSD in freebsd/freebsd-src@1cd9788.

The upstream commit fde5924dcc69 has been merged to llvm in the FreeBSD main branch so merge it here as well. Issue: llvm/llvm-project#63542

The upstream commit fde5924dcc69 has been merged to llvm in the FreeBSD main branch so merge it here as well. Issue: llvm/llvm-project#63542 (cherry picked from commit 2a9d785)

[clang] Reset FP options before template instantiation AST nodes that may depend on FP options keep them as a difference relative to the options outside the AST node. At the moment of instantiation the FP options may be different from the default values, defined by command-line option. In such case FP attributes would have unexpected values. For example, the code: template <class C> void func_01(int last, C) { func_01(last, int()); } void func_02() { func_01(0, 1); } #pragma STDC FENV_ACCESS ON caused compiler crash, because template instantiation takes place at the end of translation unit, where pragma STDC FENV_ACCESS is in effect. As a result, code in the template instantiation would use constrained intrinsics while the function does not have StrictFP attribute. To solve this problem, FP attributes in Sema must be set to default values, defined by command line options. This change resolves llvm/llvm-project#63542. Differential Revision: https://reviews.llvm.org/D154359 Requested by: pkubaj PR: 265755, 265758 MFC after: 1 month (cherry picked from commit 1cd9788)

hubert-reinterpretcast · 2023-08-10T20:03:08Z

The bad codegen reported in #63063 (comment) still occurs with this fix.

hubert-reinterpretcast · 2023-08-10T22:40:47Z

@spavloff, I have opened a regression defect against the fix: #64605
@DimitryAndric, fyi, in case you want to revert this out of FreeBSD.

llvmbot · 2023-08-10T22:45:17Z

@llvm/issue-subscribers-clang-codegen

spavloff · 2023-08-12T09:42:49Z

As I commented in #64605, this problem is not caused by fde5924, and revert of this commit does not fix the issue.

hubert-reinterpretcast · 2023-08-19T02:32:30Z

I opened #64823 for a different case that hits the same assertion.

[clang] Reset FP options before template instantiation AST nodes that may depend on FP options keep them as a difference relative to the options outside the AST node. At the moment of instantiation the FP options may be different from the default values, defined by command-line option. In such case FP attributes would have unexpected values. For example, the code: template <class C> void func_01(int last, C) { func_01(last, int()); } void func_02() { func_01(0, 1); } #pragma STDC FENV_ACCESS ON caused compiler crash, because template instantiation takes place at the end of translation unit, where pragma STDC FENV_ACCESS is in effect. As a result, code in the template instantiation would use constrained intrinsics while the function does not have StrictFP attribute. To solve this problem, FP attributes in Sema must be set to default values, defined by command line options. This change resolves llvm/llvm-project#63542. Differential Revision: https://reviews.llvm.org/D154359 Requested by: pkubaj PR: 265755, 265758 MFC after: 1 month

This is recommit of 98390cc, reverted in 82a3969, because it caused llvm/llvm-project#63542. Although the problem described in the issue is independent of the reverted patch, fail of PCH/late-parsed-instantiations.cpp indeed obseved on PowerPC and is likely to be caused by wrong serialization of `LateParsedTemplate` objects. In this patch the serialization is fixed. Original commit message is below. Previously function template instantiations occurred with FP options that were in effect at the end of translation unit. It was a problem for late template parsing as these FP options were used as attributes of AST nodes and may result in crash. To fix it FP options are set to the state of the point of template definition. Differential Revision: https://reviews.llvm.org/D143241

AST nodes that may depend on FP options keep them as a difference relative to the options outside the AST node. At the moment of instantiation the FP options may be different from the default values, defined by command-line option. In such case FP attributes would have unexpected values. For example, the code: template <class C> void func_01(int last, C) { func_01(last, int()); } void func_02() { func_01(0, 1); } #pragma STDC FENV_ACCESS ON caused compiler crash, because template instantiation takes place at the end of translation unit, where pragma STDC FENV_ACCESS is in effect. As a result, code in the template instantiation would use constrained intrinsics while the function does not have StrictFP attribute. To solve this problem, FP attributes in Sema must be set to default values, defined by command line options. This change resolves llvm/llvm-project#63542. Differential Revision: https://reviews.llvm.org/D154359

github-actions bot added the new issue label Jun 27, 2023

EugeneZelenko added llvm:codegen crash Prefer [crash-on-valid] or [crash-on-invalid] and removed new issue labels Jun 27, 2023

DimitryAndric added the floating-point Floating-point math label Jun 28, 2023

spavloff added a commit that referenced this issue Jun 28, 2023

Revert "[Clang] Reset FP options before function instantiations"

82a3969

This reverts commit 98390cc. It caused issue #63542.

spavloff closed this as completed in fde5924 Jul 13, 2023

EugeneZelenko added clang:frontend Language frontend issues, e.g. anything involving "Sema" and removed llvm:codegen labels Jul 13, 2023

freebsd-git pushed a commit to freebsd/freebsd-ports that referenced this issue Jul 14, 2023

devel/llvm16: backport upstream powerpc FP fix

2a9d785

The upstream commit fde5924dcc69 has been merged to llvm in the FreeBSD main branch so merge it here as well. Issue: llvm/llvm-project#63542

EugeneZelenko added clang:codegen IR generation bugs: mangling, exceptions, etc. and removed clang:frontend Language frontend issues, e.g. anything involving "Sema" labels Aug 10, 2023

spavloff mentioned this issue Aug 17, 2023

[Regression 16 -> 17] Template instantiation ignores FENV_ACCESS being ON for both definition and instantiation #64605

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pkubaj commented Jun 27, 2023 •

edited

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spavloff commented Aug 12, 2023

hubert-reinterpretcast commented Aug 19, 2023

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pkubaj commented Jun 27, 2023 • edited Loading

VoxSciurorum commented Jun 27, 2023

pkubaj commented Jun 27, 2023

VoxSciurorum commented Jun 27, 2023

DimitryAndric commented Jun 28, 2023

spavloff commented Jul 5, 2023

llvmbot commented Jul 13, 2023

pkubaj commented Jul 13, 2023

pkubaj commented Jul 13, 2023

DimitryAndric commented Jul 13, 2023

hubert-reinterpretcast commented Aug 10, 2023

hubert-reinterpretcast commented Aug 10, 2023

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spavloff commented Aug 12, 2023

hubert-reinterpretcast commented Aug 19, 2023

pkubaj commented Jun 27, 2023 •

edited

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