craig.topper created this revision.
The fma libcalls are defined in Builtins.def using the 'e' attribute that says
that its only const if -fno-math-errno. It was apparently marked this way
because that's what the posix spec says. This determines whether the call gets
marked as const or not in SemaDecl.cpp. But in CGBuiltins.cpp we are blindly
emitting an intrinsic no matter whether the call is const or not.
This patch changes Builtins.def to match the current CGBuiltins behavior and
updates CGBuiltins to check if the function is const. So if anyone ever changes
Builtins.def in the future it will do the right thing.
https://reviews.llvm.org/D30922
Files:
include/clang/Basic/Builtins.def
lib/CodeGen/CGBuiltin.cpp
Index: lib/CodeGen/CGBuiltin.cpp
===================================================================
--- lib/CodeGen/CGBuiltin.cpp
+++ lib/CodeGen/CGBuiltin.cpp
@@ -1898,6 +1898,8 @@
case Builtin::BI__builtin_fmaf:
case Builtin::BI__builtin_fmal: {
// Rewrite fma to intrinsic.
+ if (!FD->hasAttr<ConstAttr>())
+ break;
Value *FirstArg = EmitScalarExpr(E->getArg(0));
llvm::Type *ArgType = FirstArg->getType();
Value *F = CGM.getIntrinsic(Intrinsic::fma, ArgType);
Index: include/clang/Basic/Builtins.def
===================================================================
--- include/clang/Basic/Builtins.def
+++ include/clang/Basic/Builtins.def
@@ -1067,9 +1067,10 @@
LIBBUILTIN(floorf, "ff", "fnc", "math.h", ALL_LANGUAGES)
LIBBUILTIN(floorl, "LdLd", "fnc", "math.h", ALL_LANGUAGES)
-LIBBUILTIN(fma, "dddd", "fne", "math.h", ALL_LANGUAGES)
-LIBBUILTIN(fmaf, "ffff", "fne", "math.h", ALL_LANGUAGES)
-LIBBUILTIN(fmal, "LdLdLdLd", "fne", "math.h", ALL_LANGUAGES)
+// Posix standard says this updates errno, but we always emit an intrinsic.
+LIBBUILTIN(fma, "dddd", "fnc", "math.h", ALL_LANGUAGES)
+LIBBUILTIN(fmaf, "ffff", "fnc", "math.h", ALL_LANGUAGES)
+LIBBUILTIN(fmal, "LdLdLdLd", "fnc", "math.h", ALL_LANGUAGES)
LIBBUILTIN(fmax, "ddd", "fnc", "math.h", ALL_LANGUAGES)
LIBBUILTIN(fmaxf, "fff", "fnc", "math.h", ALL_LANGUAGES)
Index: lib/CodeGen/CGBuiltin.cpp
===================================================================
--- lib/CodeGen/CGBuiltin.cpp
+++ lib/CodeGen/CGBuiltin.cpp
@@ -1898,6 +1898,8 @@
case Builtin::BI__builtin_fmaf:
case Builtin::BI__builtin_fmal: {
// Rewrite fma to intrinsic.
+ if (!FD->hasAttr<ConstAttr>())
+ break;
Value *FirstArg = EmitScalarExpr(E->getArg(0));
llvm::Type *ArgType = FirstArg->getType();
Value *F = CGM.getIntrinsic(Intrinsic::fma, ArgType);
Index: include/clang/Basic/Builtins.def
===================================================================
--- include/clang/Basic/Builtins.def
+++ include/clang/Basic/Builtins.def
@@ -1067,9 +1067,10 @@
LIBBUILTIN(floorf, "ff", "fnc", "math.h", ALL_LANGUAGES)
LIBBUILTIN(floorl, "LdLd", "fnc", "math.h", ALL_LANGUAGES)
-LIBBUILTIN(fma, "dddd", "fne", "math.h", ALL_LANGUAGES)
-LIBBUILTIN(fmaf, "ffff", "fne", "math.h", ALL_LANGUAGES)
-LIBBUILTIN(fmal, "LdLdLdLd", "fne", "math.h", ALL_LANGUAGES)
+// Posix standard says this updates errno, but we always emit an intrinsic.
+LIBBUILTIN(fma, "dddd", "fnc", "math.h", ALL_LANGUAGES)
+LIBBUILTIN(fmaf, "ffff", "fnc", "math.h", ALL_LANGUAGES)
+LIBBUILTIN(fmal, "LdLdLdLd", "fnc", "math.h", ALL_LANGUAGES)
LIBBUILTIN(fmax, "ddd", "fnc", "math.h", ALL_LANGUAGES)
LIBBUILTIN(fmaxf, "fff", "fnc", "math.h", ALL_LANGUAGES)
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