rsmith added inline comments.
================
Comment at: clang/lib/AST/ExprConstant.cpp:2683
}
+ if (const BinaryOperator *BE = dyn_cast<BinaryOperator>(E)) {
+ if (BE->getFPFeaturesInEffect(Info.Ctx.getLangOpts()).isFPConstrained()) {
----------------
`E` here is only intended for use in determining diagnostic locations, and
isn't intended to necessarily be the expression being evaluated. Instead of
assuming that this is the right expression to inspect, please either query the
FP features in the caller and pass them into here or change this function to
take a `const BinaryOperator*`.
================
Comment at: clang/lib/AST/ExprConstant.cpp:2685
+ if (BE->getFPFeaturesInEffect(Info.Ctx.getLangOpts()).isFPConstrained()) {
+ Info.CCEDiag(E, diag::note_constexpr_float_arithmetic_strict);
+ return false;
----------------
This should be an `FFDiag` not a `CCEDiag` because we want to suppress all
constant folding, not only treating the value as a core constant expression.
Also we should check this before checking for a NaN result, because if both
happen at once, this is the diagnostic we want to produce.
================
Comment at: clang/lib/AST/ExprConstant.cpp:13283-13286
+ if (E->getFPFeaturesInEffect(Info.Ctx.getLangOpts()).isFPConstrained()) {
+ Info.CCEDiag(E, diag::note_constexpr_float_arithmetic_strict);
+ return false;
+ }
----------------
Hm, does `fabs` depend on the floating-point environment? Is the concern the
interaction with signaling NaNs?
================
Comment at: clang/lib/AST/ExprConstant.cpp:13372-13376
+ if (E->getFPFeaturesInEffect(Info.Ctx.getLangOpts()).isFPConstrained()) {
+ // In C lang ref, footnote, cast may raise inexact exception.
+ Info.CCEDiag(E, diag::note_constexpr_float_arithmetic_strict);
+ return false;
+ }
----------------
Is it feasible to only reject cases that would actually be inexact, rather than
disallowing all conversions to floating-point types? It would seem preferable
to allow at least widening FP conversions and complex -> real, since they never
depend on the FP environment (right?).
================
Comment at: clang/test/CodeGen/pragma-fenv_access.c:1
+// xxx: %clang_cc1 -ffp-exception-behavior=strict -frounding-math -triple
%itanium_abi_triple -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang_cc1 -ffp-exception-behavior=strict -triple %itanium_abi_triple
-emit-llvm %s -o - | FileCheck %s
----------------
Is this RUN line intentionally disabled?
Repository:
rG LLVM Github Monorepo
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
