mibintc added inline comments.
================ Comment at: clang/test/CodeGen/fp-floatcontrol-pragma.cpp:154 + if (i<0) + return 1.0 + 2.0; + // Check that floating point constant folding doesn't occur if ---------------- sepavloff wrote: > In this particular case we know for sure that the result does not depend on > rounding mode and no FP exceptions occurs, so it is safe to constfold the > expression. > > Expressions like `1.0 / 0.0` or `1.0F + 0x0.000001p0F` indeed may require > execution in runtime, depending on the required exception handling. I would > propose to connect their const-evaluability with `FPExceptionMode` and set > the latter to `strict` whenever `AllowFEnvAccess` is set to `true`. Thank you, I will study these remarks. BTW I had inserted checks to verify semantic rules about the use of pragma float_control and fenv_access, to follow what Microsoft describes on this page, https://docs.microsoft.com/en-us/cpp/preprocessor/fenv-access?view=vs-2019 Quoting: There are restrictions on the ways you can use the fenv_access pragma in combination with other floating-point settings: You can't enable fenv_access unless precise semantics are enabled. Precise semantics can be enabled either by the float_control pragma, or by using the /fp:precise or /fp:strict compiler options. The compiler defaults to /fp:precise if no other floating-point command-line option is specified. You can't use float_control to disable precise semantics when fenv_access(on) is set. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D87528/new/ https://reviews.llvm.org/D87528 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
