[flang] Modifications to ieee_support_standard

[vdonaldson]

The result of a call to ieee_support_halting is one of the components that affect the result of a call to ieee_support_standard.

[llvmbot]

@llvm/pr-subscribers-flang-semantics

Author: None (vdonaldson)

Changes

The result of a call to ieee_support_halting is one of the components that affect the result of a call to ieee_support_standard.

---

Full diff: https://github.com/llvm/llvm-project/pull/125967.diff

2 Files Affected:

• (modified) flang/include/flang/Evaluate/target.h (+4-3)
• (modified) flang/include/flang/Tools/TargetSetup.h (+2-2)

diff --git a/flang/include/flang/Evaluate/target.h b/flang/include/flang/Evaluate/target.h
index e07f916b875e06b..44c552b99cf4eaa 100644
--- a/flang/include/flang/Evaluate/target.h
+++ b/flang/include/flang/Evaluate/target.h
@@ -143,9 +143,10 @@ class TargetCharacteristics {
   std::string compilerOptionsString_;
   std::string compilerVersionString_;
   IeeeFeatures ieeeFeatures_{IeeeFeature::Denormal, IeeeFeature::Divide,
-      IeeeFeature::Flags, IeeeFeature::Inf, IeeeFeature::Io, IeeeFeature::NaN,
-      IeeeFeature::Rounding, IeeeFeature::Sqrt, IeeeFeature::Standard,
-      IeeeFeature::Subnormal, IeeeFeature::UnderflowControl};
+      IeeeFeature::Flags, IeeeFeature::Halting, IeeeFeature::Inf,
+      IeeeFeature::Io, IeeeFeature::NaN, IeeeFeature::Rounding,
+      IeeeFeature::Sqrt, IeeeFeature::Standard, IeeeFeature::Subnormal,
+      IeeeFeature::UnderflowControl};
 };
 
 } // namespace Fortran::evaluate
diff --git a/flang/include/flang/Tools/TargetSetup.h b/flang/include/flang/Tools/TargetSetup.h
index 5d23df6823a9485..d167f44fe2fd770 100644
--- a/flang/include/flang/Tools/TargetSetup.h
+++ b/flang/include/flang/Tools/TargetSetup.h
@@ -25,8 +25,6 @@ namespace Fortran::tools {
 
   const llvm::Triple &targetTriple{targetMachine.getTargetTriple()};
 
-  targetCharacteristics.set_ieeeFeature(evaluate::IeeeFeature::Halting, true);
-
   if (targetTriple.getArch() == llvm::Triple::ArchType::x86_64) {
     targetCharacteristics.set_hasSubnormalFlushingControl(/*kind=*/3);
     targetCharacteristics.set_hasSubnormalFlushingControl(/*kind=*/4);
@@ -37,6 +35,8 @@ namespace Fortran::tools {
     targetCharacteristics.set_haltingSupportIsUnknownAtCompileTime();
     targetCharacteristics.set_ieeeFeature(
         evaluate::IeeeFeature::Halting, false);
+    targetCharacteristics.set_ieeeFeature(
+        evaluate::IeeeFeature::Standard, false);
     targetCharacteristics.set_hasSubnormalFlushingControl(/*kind=*/3);
     targetCharacteristics.set_hasSubnormalFlushingControl(/*kind=*/4);
     targetCharacteristics.set_hasSubnormalFlushingControl(/*kind=*/8);

[jeanPerier]

LGTM, I added @kiranchandramohan and @pawosm-arm for visibility since this is about ARM.

[llvm-ci]

LLVM Buildbot has detected a new failure on builder flang-aarch64-libcxx running on linaro-flang-aarch64-libcxx while building flang at step 6 "test-build-unified-tree-check-flang".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/89/builds/16156

Here is the relevant piece of the build log for the reference

Step 6 (test-build-unified-tree-check-flang) failure: test (failure)
******************** TEST 'Flang :: Evaluate/fold-ieee.f90' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
Not assuming libpgmath support
Folding test failed:
test_std_4 .false._4
test_std_8 .false._4
test_std_all .false._4

FAIL

--
Command Output (stderr):
--
RUN: at line 1: "/usr/bin/python3.10" /home/tcwg-buildbot/worker/flang-aarch64-libcxx/llvm-project/flang/test/Evaluate/test_folding.py /home/tcwg-buildbot/worker/flang-aarch64-libcxx/llvm-project/flang/test/Evaluate/fold-ieee.f90 /home/tcwg-buildbot/worker/flang-aarch64-libcxx/build/bin/flang -fc1
+ /usr/bin/python3.10 /home/tcwg-buildbot/worker/flang-aarch64-libcxx/llvm-project/flang/test/Evaluate/test_folding.py /home/tcwg-buildbot/worker/flang-aarch64-libcxx/llvm-project/flang/test/Evaluate/fold-ieee.f90 /home/tcwg-buildbot/worker/flang-aarch64-libcxx/build/bin/flang -fc1

--

********************

[llvm-ci]

LLVM Buildbot has detected a new failure on builder flang-aarch64-latest-gcc running on linaro-flang-aarch64-latest-gcc while building flang at step 6 "test-build-unified-tree-check-flang".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/130/builds/9666

Here is the relevant piece of the build log for the reference

Step 6 (test-build-unified-tree-check-flang) failure: test (failure)
******************** TEST 'Flang :: Evaluate/folding18.f90' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
Not assuming libpgmath support
Folding test failed:
test_ieee_support_standard .false._4

FAIL

--
Command Output (stderr):
--
RUN: at line 1: "/usr/bin/python3.10" /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/llvm-project/flang/test/Evaluate/test_folding.py /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/llvm-project/flang/test/Evaluate/folding18.f90 /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/bin/flang -fc1
+ /usr/bin/python3.10 /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/llvm-project/flang/test/Evaluate/test_folding.py /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/llvm-project/flang/test/Evaluate/folding18.f90 /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/bin/flang -fc1

--

********************

[llvm-ci]

LLVM Buildbot has detected a new failure on builder flang-aarch64-release running on linaro-flang-aarch64-release while building flang at step 6 "test-build-unified-tree-check-flang".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/172/builds/9337

Here is the relevant piece of the build log for the reference

Step 6 (test-build-unified-tree-check-flang) failure: test (failure)
******************** TEST 'Flang :: Evaluate/fold-ieee.f90' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
Not assuming libpgmath support
Folding test failed:
test_std_4 .false._4
test_std_8 .false._4
test_std_all .false._4

FAIL

--
Command Output (stderr):
--
RUN: at line 1: "/usr/bin/python3.10" /home/tcwg-buildbot/worker/flang-aarch64-release/llvm-project/flang/test/Evaluate/test_folding.py /home/tcwg-buildbot/worker/flang-aarch64-release/llvm-project/flang/test/Evaluate/fold-ieee.f90 /home/tcwg-buildbot/worker/flang-aarch64-release/build/bin/flang -fc1
+ /usr/bin/python3.10 /home/tcwg-buildbot/worker/flang-aarch64-release/llvm-project/flang/test/Evaluate/test_folding.py /home/tcwg-buildbot/worker/flang-aarch64-release/llvm-project/flang/test/Evaluate/fold-ieee.f90 /home/tcwg-buildbot/worker/flang-aarch64-release/build/bin/flang -fc1

--

********************

[tblah]

Since this commit (and the later fix for the buildbots), this Fujitsu test started failing on my aarch64 machine (printing "err") https://github.com/fujitsu/compiler-test-suite/blob/main/Fortran/0136/0136_0045.f90

To reproduce compile and run the test file.

Please could you take a look.

[vdonaldson]

Since this commit, this Fujitsu test started failing on my aarch64 machine (printing "err")

The Fujitsu test behavior was intentional because ieee_support_standard depends on ieee_support_halting, which may return false on Arm. But the test call is in executable code, so it may be possible to change this the same way the halting control call can return true in runtime code. I'll take another look. Thanks for the pointer.