[llvm] DAG: Gracefully diagnose missing FP conversion libcalls when softening (PR #215765)

[via llvm-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Linux-->
# :penguin: Linux x64 Test Results

The build failed before running any tests. Click on a failure below to see the details.

<details>
<summary>lib/CodeGen/SelectionDAG/CMakeFiles/LLVMSelectionDAG.dir/LegalizeFloatTypes.cpp.o</summary>

```
FAILED: lib/CodeGen/SelectionDAG/CMakeFiles/LLVMSelectionDAG.dir/LegalizeFloatTypes.cpp.o
sccache /opt/llvm/bin/clang++ -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_USE_CXX11_ABI=1 -D_GNU_SOURCE -D_LIBCPP_HARDENING_MODE=_LIBCPP_HARDENING_MODE_EXTENSIVE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/gha/actions-runner/_work/llvm-project/llvm-project/build/lib/CodeGen/SelectionDAG -I/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG -I/home/gha/actions-runner/_work/llvm-project/llvm-project/build/include -I/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/include -gmlt -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wno-pass-failed -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -std=c++17 -UNDEBUG -fno-exceptions -funwind-tables -fno-rtti -MD -MT lib/CodeGen/SelectionDAG/CMakeFiles/LLVMSelectionDAG.dir/LegalizeFloatTypes.cpp.o -MF lib/CodeGen/SelectionDAG/CMakeFiles/LLVMSelectionDAG.dir/LegalizeFloatTypes.cpp.o.d -o lib/CodeGen/SelectionDAG/CMakeFiles/LLVMSelectionDAG.dir/LegalizeFloatTypes.cpp.o -c /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp:666:12: error: use of undeclared identifier 'SoftenFloatRes_NoLibcall'; did you mean 'SoftenFloatRes_Binary'?
666 |     return SoftenFloatRes_NoLibcall(N, NVT);
|            ^~~~~~~~~~~~~~~~~~~~~~~~
|            SoftenFloatRes_Binary
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp:211:27: note: 'SoftenFloatRes_Binary' declared here
211 | SDValue DAGTypeLegalizer::SoftenFloatRes_Binary(SDNode *N, RTLIB::Libcall LC) {
|                           ^
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp:666:40: error: no viable conversion from 'EVT' to 'RTLIB::Libcall'
666 |     return SoftenFloatRes_NoLibcall(N, NVT);
|                                        ^~~
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp:211:75: note: passing argument to parameter 'LC' here
211 | SDValue DAGTypeLegalizer::SoftenFloatRes_Binary(SDNode *N, RTLIB::Libcall LC) {
|                                                                           ^
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp:720:12: error: use of undeclared identifier 'SoftenFloatRes_NoLibcall'; did you mean 'SoftenFloatRes_Binary'?
720 |     return SoftenFloatRes_NoLibcall(N, NVT);
|            ^~~~~~~~~~~~~~~~~~~~~~~~
|            SoftenFloatRes_Binary
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp:211:27: note: 'SoftenFloatRes_Binary' declared here
211 | SDValue DAGTypeLegalizer::SoftenFloatRes_Binary(SDNode *N, RTLIB::Libcall LC) {
|                           ^
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp:720:40: error: no viable conversion from 'EVT' to 'RTLIB::Libcall'
720 |     return SoftenFloatRes_NoLibcall(N, NVT);
|                                        ^~~
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp:211:75: note: passing argument to parameter 'LC' here
211 | SDValue DAGTypeLegalizer::SoftenFloatRes_Binary(SDNode *N, RTLIB::Libcall LC) {
|                                                                           ^
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp:1128:12: error: use of undeclared identifier 'SoftenFloatRes_NoLibcall'; did you mean 'SoftenFloatRes_Binary'?
1128 |     return SoftenFloatRes_NoLibcall(N, NRVT);
|            ^~~~~~~~~~~~~~~~~~~~~~~~
|            SoftenFloatRes_Binary
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp:211:27: note: 'SoftenFloatRes_Binary' declared here
211 | SDValue DAGTypeLegalizer::SoftenFloatRes_Binary(SDNode *N, RTLIB::Libcall LC) {
|                           ^
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp:1128:40: error: no viable conversion from 'EVT' to 'RTLIB::Libcall'
1128 |     return SoftenFloatRes_NoLibcall(N, NRVT);
|                                        ^~~~
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp:211:75: note: passing argument to parameter 'LC' here
211 | SDValue DAGTypeLegalizer::SoftenFloatRes_Binary(SDNode *N, RTLIB::Libcall LC) {
|                                                                           ^
6 errors generated.
```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/215765