@llvm.sqrt isn't really close enough to C's sqrt to justify emitting calls
to the intrinsic, even when math-errno is off.
Fixes rdar://problem/7828230 by falling back on the library function.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@100613 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index 38c40ed..a46cc39 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -682,13 +682,12 @@
case Builtin::BIsqrt:
case Builtin::BIsqrtf:
case Builtin::BIsqrtl: {
- // Rewrite sqrt to intrinsic if allowed.
- if (!FD->hasAttr<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"));
+ // TODO: there is currently no set of optimizer flags
+ // sufficient for us to rewrite sqrt to @llvm.sqrt.
+ // -fmath-errno=0 is not good enough; we need finiteness.
+ // We could probably precondition the call with an ult
+ // against 0, but is that worth the complexity?
+ break;
}
case Builtin::BIpow:
diff --git a/test/CodeGen/libcalls.c b/test/CodeGen/libcalls.c
index a96176a..828d7de 100644
--- a/test/CodeGen/libcalls.c
+++ b/test/CodeGen/libcalls.c
@@ -1,22 +1,52 @@
-// RUN: %clang_cc1 -fmath-errno -emit-llvm -o %t %s -triple i386-unknown-unknown
-// RUN: grep "declare " %t | count 6
-// RUN: grep "declare " %t | grep "@llvm." | count 1
-// RUN: %clang_cc1 -emit-llvm -o %t %s -triple i386-unknown-unknown
-// RUN: grep "declare " %t | count 6
-// RUN: grep "declare " %t | grep -v "@llvm." | count 0
+// RUN: %clang_cc1 -fmath-errno -emit-llvm -o - %s -triple i386-unknown-unknown | FileCheck -check-prefix YES %s
+// RUN: %clang_cc1 -emit-llvm -o - %s -triple i386-unknown-unknown | FileCheck -check-prefix NO %s
-// IRgen only pays attention to const; it should always call llvm for
-// this.
-float sqrtf(float) __attribute__((const));
-
+// CHECK-YES: define void @test_sqrt
+// CHECK-NO: define void @test_sqrt
void test_sqrt(float a0, double a1, long double a2) {
+ // Following llvm-gcc's lead, we never emit these as intrinsics;
+ // no-math-errno isn't good enough. We could probably use intrinsics
+ // with appropriate guards if it proves worthwhile.
+
+ // CHECK-YES: call float @sqrtf
+ // CHECK-NO: call float @sqrtf
float l0 = sqrtf(a0);
+
+ // CHECK-YES: call double @sqrt
+ // CHECK-NO: call double @sqrt
double l1 = sqrt(a1);
+
+ // CHECK-YES: call x86_fp80 @sqrtl
+ // CHECK-NO: call x86_fp80 @sqrtl
long double l2 = sqrtl(a2);
}
+// CHECK-YES: declare float @sqrtf(float)
+// CHECK-YES: declare double @sqrt(double)
+// CHECK-YES: declare x86_fp80 @sqrtl(x86_fp80)
+// CHECK-NO: declare float @sqrtf(float) readnone
+// CHECK-NO: declare double @sqrt(double) readnone
+// CHECK-NO: declare x86_fp80 @sqrtl(x86_fp80) readnone
+
+// CHECK-YES: define void @test_pow
+// CHECK-NO: define void @test_pow
void test_pow(float a0, double a1, long double a2) {
+ // CHECK-YES: call float @powf
+ // CHECK-NO: call float @llvm.pow.f32
float l0 = powf(a0, a0);
+
+ // CHECK-YES: call double @pow
+ // CHECK-NO: call double @llvm.pow.f64
double l1 = pow(a1, a1);
+
+ // CHECK-YES: call x86_fp80 @powl
+ // CHECK-NO: call x86_fp80 @llvm.pow.f80
long double l2 = powl(a2, a2);
}
+
+// CHECK-YES: declare float @powf(float, float)
+// CHECK-YES: declare double @pow(double, double)
+// CHECK-YES: declare x86_fp80 @powl(x86_fp80, x86_fp80)
+// CHECK-NO: declare float @llvm.pow.f32(float, float) nounwind readonly
+// CHECK-NO: declare double @llvm.pow.f64(double, double) nounwind readonly
+// CHECK-NO: declare x86_fp80 @llvm.pow.f80(x86_fp80, x86_fp80) nounwind readonly