[Driver] Clean up denormal handling with fast-math-related options (#89477)
This change cleans up the clang driver handling of umbrella options like
-ffast-math, -funsafe-math-optimizations, and -ffp-model, and aligns the
behavior of -ffp-model=fast with -ffast-math with regard to the linking
of crtfastmath.o.
We agreed in a previous review that the fast-math options should not
attempt to change the -fdenormal-fp-math option, which is inherently
target-specific.
The clang user's manual claims that -ffp-model=fast "behaves identically
to specifying both -ffast-math and -ffp-contract=fast." Since
-ffast-math causes crtfastmath.o to be linked if it is available, that should
also happen with -ffp-model=fast.
I am going to be proposing further changes to -ffp-model=fast,
decoupling it from -ffast-math and introducing a new
-ffp-model=aggressive that matches the current behavior, but I wanted
to solidfy the current behavior before I do that.
diff --git a/clang/test/Driver/solaris-ld.c b/clang/test/Driver/solaris-ld.c
index 6d74389..ce0728d 100644
--- a/clang/test/Driver/solaris-ld.c
+++ b/clang/test/Driver/solaris-ld.c
@@ -193,6 +193,9 @@
// RUN: %clang --target=sparc-sun-solaris2.11 -### %s -ffast-math \
// RUN: --sysroot=%S/Inputs/solaris_sparc_tree 2>&1 \
// RUN: | FileCheck --check-prefix=CHECK-CRTFASTMATH-SPARC32 %s
+// RUN: %clang --target=sparc-sun-solaris2.11 -### %s -ffp-model=fast \
+// RUN: --sysroot=%S/Inputs/solaris_sparc_tree 2>&1 \
+// RUN: | FileCheck --check-prefix=CHECK-CRTFASTMATH-SPARC32 %s
// CHECK-CRTFASTMATH-SPARC32: "-isysroot" "[[SYSROOT:[^"]+]]"
// CHECK-CRTFASTMATH-SPARC32: "[[SYSROOT]]/usr/gcc/4.8/lib/gcc/sparc-sun-solaris2.11/4.8.2{{/|\\\\}}crtfastmath.o"
// CHECK-NOCRTFASTMATH-SPARC32-NOT: crtfastmath.o
