Support IRgen of sqrt -> llvm.sqrt, pow -> llvm.pow.
- Define pow[lf]?, sqrt[lf]? as builtins.
- Add -fmath-errno option which binds to LangOptions.MathErrno
- Add new builtin flag Builtin::Context::isConstWithoutErrno for
functions which can be marked as const if errno isn't respected for
math functions. Sema automatically marks these functions as const
when they are defined, if MathErrno=0.
- IRgen uses const attribute on sqrt and pow library functions to
decide if it can use the llvm intrinsic.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64689 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index b990c19..6e59226 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -36,7 +36,8 @@
CFG.EmitScalarExpr(E->getArg(1))));
}
-RValue CodeGenFunction::EmitBuiltinExpr(unsigned BuiltinID, const CallExpr *E) {
+RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
+ unsigned BuiltinID, const CallExpr *E) {
// See if we can constant fold this builtin. If so, don't emit it at all.
Expr::EvalResult Result;
if (E->Evaluate(Result, CGM.getContext())) {
@@ -324,6 +325,34 @@
}
case Builtin::BI__sync_lock_test_and_set:
return EmitBinaryAtomic(*this, Intrinsic::atomic_swap, E);
+
+
+ // Library functions with special handling.
+
+ case Builtin::BIsqrt:
+ case Builtin::BIsqrtf:
+ case Builtin::BIsqrtl: {
+ // Rewrite sqrt to intrinsic if allowed.
+ if (!FD->getAttr<ConstAttr>())
+ break;
+ Value *Arg0 = EmitScalarExpr(E->getArg(0));
+ const llvm::Type *ArgType = Arg0->getType();
+ Value *F = CGM.getIntrinsic(Intrinsic::sqrt, &ArgType, 1);
+ return RValue::get(Builder.CreateCall(F, Arg0, "tmp"));
+ }
+
+ case Builtin::BIpow:
+ case Builtin::BIpowf:
+ case Builtin::BIpowl: {
+ // Rewrite sqrt to intrinsic if allowed.
+ if (!FD->getAttr<ConstAttr>())
+ break;
+ Value *Base = EmitScalarExpr(E->getArg(0));
+ Value *Exponent = EmitScalarExpr(E->getArg(1));
+ const llvm::Type *ArgType = Base->getType();
+ Value *F = CGM.getIntrinsic(Intrinsic::pow, &ArgType, 1);
+ return RValue::get(Builder.CreateCall2(F, Base, Exponent, "tmp"));
+ }
}
// If this is an alias for a libm function (e.g. __builtin_sin) turn it into
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 4dc8a9e..b151dd2 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -969,7 +969,7 @@
if (const FunctionDecl *FDecl =
dyn_cast<const FunctionDecl>(DRExpr->getDecl()))
if (unsigned builtinID = FDecl->getBuiltinID(getContext()))
- return EmitBuiltinExpr(builtinID, E);
+ return EmitBuiltinExpr(FDecl, builtinID, E);
if (E->getCallee()->getType()->isBlockPointerType())
return EmitBlockCallExpr(E);
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 5f42a42..7f36c71 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -631,7 +631,8 @@
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd);
- RValue EmitBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
+ RValue EmitBuiltinExpr(const FunctionDecl *FD,
+ unsigned BuiltinID, const CallExpr *E);
RValue EmitBlockCallExpr(const CallExpr *E);