[libcxx-commits] [clang] [libcxx] [PowerPC] Emit libcall to frexpl for calls to frexp(ppcDoublDouble) (PR #75226)
Lei Huang via libcxx-commits
libcxx-commits at lists.llvm.org
Thu Dec 14 09:39:43 PST 2023
https://github.com/lei137 updated https://github.com/llvm/llvm-project/pull/75226
>From 6819814317367cf7fc944a5a1ecedd357bc3cd0a Mon Sep 17 00:00:00 2001
From: Lei Huang <lei at ca.ibm.com>
Date: Tue, 12 Dec 2023 10:58:34 -0600
Subject: [PATCH 1/3] [PowerPC] Emit libcall to frexpl for calls to
frexp(ppcDoublDouble)
On Linux PPC call lib func ``frexpl`` for calls to ``frexp()`` for input
of type PPCDoubleDouble.
Fixes bug: https://github.com/llvm/llvm-project/issues/64426
---
clang/lib/CodeGen/CGBuiltin.cpp | 17 ++++++++++++++++-
.../c.math/constexpr-cxx23-clang.pass.cpp | 6 ------
2 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 353b7930b3c1ea..e733bbf8be8b71 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -137,6 +137,10 @@ llvm::Constant *CodeGenModule::getBuiltinLibFunction(const FunctionDecl *FD,
{Builtin::BI__builtin_modfl, "modf"},
};
+ static SmallDenseMap<unsigned, StringRef, 4> PPCDoubleDoubleBuiltins{
+ {Builtin::BI__builtin_frexpl, "frexpl"},
+ };
+
// If the builtin has been declared explicitly with an assembler label,
// use the mangled name. This differs from the plain label on platforms
// that prefix labels.
@@ -149,6 +153,11 @@ llvm::Constant *CodeGenModule::getBuiltinLibFunction(const FunctionDecl *FD,
&getTarget().getLongDoubleFormat() == &llvm::APFloat::IEEEquad() &&
F128Builtins.contains(BuiltinID))
Name = F128Builtins[BuiltinID];
+ else if (getTriple().isPPC() && getTriple().isOSLinux() &&
+ &getTarget().getLongDoubleFormat() ==
+ &llvm::APFloat::PPCDoubleDouble() &&
+ PPCDoubleDoubleBuiltins.contains(BuiltinID))
+ Name = PPCDoubleDoubleBuiltins[BuiltinID];
else if (getTriple().isOSAIX() &&
&getTarget().getLongDoubleFormat() ==
&llvm::APFloat::IEEEdouble() &&
@@ -3410,9 +3419,15 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
{ Src0->getType(), Src1->getType() });
return RValue::get(Builder.CreateCall(F, { Src0, Src1 }));
}
+ case Builtin::BI__builtin_frexpl: {
+ auto &Triple = getTarget().getTriple();
+ if (Triple.isPPC() && Triple.isOSLinux() &&
+ &getTarget().getLongDoubleFormat() == &llvm::APFloat::PPCDoubleDouble())
+ break;
+ LLVM_FALLTHROUGH;
+ }
case Builtin::BI__builtin_frexp:
case Builtin::BI__builtin_frexpf:
- case Builtin::BI__builtin_frexpl:
case Builtin::BI__builtin_frexpf128:
case Builtin::BI__builtin_frexpf16:
return RValue::get(emitFrexpBuiltin(*this, E, Intrinsic::frexp));
diff --git a/libcxx/test/libcxx/numerics/c.math/constexpr-cxx23-clang.pass.cpp b/libcxx/test/libcxx/numerics/c.math/constexpr-cxx23-clang.pass.cpp
index 31511064ce7ca5..a07260a34516f1 100644
--- a/libcxx/test/libcxx/numerics/c.math/constexpr-cxx23-clang.pass.cpp
+++ b/libcxx/test/libcxx/numerics/c.math/constexpr-cxx23-clang.pass.cpp
@@ -58,15 +58,9 @@ int main(int, char**) {
ASSERT_NOT_CONSTEXPR_CXX23(std::frexp(0.0f, &DummyInt) == 0.0f);
ASSERT_NOT_CONSTEXPR_CXX23(std::frexp(0.0, &DummyInt) == 0.0);
-//FIXME: currently linux powerpc does not support this expansion
-// since 0.0L lowers to ppcf128 and special handling is required.
-#if !defined(__LONG_DOUBLE_IBM128__)
ASSERT_NOT_CONSTEXPR_CXX23(std::frexp(0.0L, &DummyInt) == 0.0L);
-#endif
ASSERT_NOT_CONSTEXPR_CXX23(std::frexpf(0.0f, &DummyInt) == 0.0f);
-#if !defined(__LONG_DOUBLE_IBM128__)
ASSERT_NOT_CONSTEXPR_CXX23(std::frexpl(0.0L, &DummyInt) == 0.0L);
-#endif
ASSERT_NOT_CONSTEXPR_CXX23(std::ilogb(1.0f) == 0);
ASSERT_NOT_CONSTEXPR_CXX23(std::ilogb(1.0) == 0);
>From d230bb9f415f9adf4099ef911459b67c692ccd3e Mon Sep 17 00:00:00 2001
From: Lei Huang <lei at ca.ibm.com>
Date: Thu, 14 Dec 2023 09:28:50 -0600
Subject: [PATCH 2/3] address Eli's review comments
---
clang/lib/CodeGen/CGBuiltin.cpp | 15 ++++-----------
clang/test/CodeGen/math-builtins-long.c | 2 +-
2 files changed, 5 insertions(+), 12 deletions(-)
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index e733bbf8be8b71..73df0ef99f853c 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -137,10 +137,6 @@ llvm::Constant *CodeGenModule::getBuiltinLibFunction(const FunctionDecl *FD,
{Builtin::BI__builtin_modfl, "modf"},
};
- static SmallDenseMap<unsigned, StringRef, 4> PPCDoubleDoubleBuiltins{
- {Builtin::BI__builtin_frexpl, "frexpl"},
- };
-
// If the builtin has been declared explicitly with an assembler label,
// use the mangled name. This differs from the plain label on platforms
// that prefix labels.
@@ -153,11 +149,6 @@ llvm::Constant *CodeGenModule::getBuiltinLibFunction(const FunctionDecl *FD,
&getTarget().getLongDoubleFormat() == &llvm::APFloat::IEEEquad() &&
F128Builtins.contains(BuiltinID))
Name = F128Builtins[BuiltinID];
- else if (getTriple().isPPC() && getTriple().isOSLinux() &&
- &getTarget().getLongDoubleFormat() ==
- &llvm::APFloat::PPCDoubleDouble() &&
- PPCDoubleDoubleBuiltins.contains(BuiltinID))
- Name = PPCDoubleDoubleBuiltins[BuiltinID];
else if (getTriple().isOSAIX() &&
&getTarget().getLongDoubleFormat() ==
&llvm::APFloat::IEEEdouble() &&
@@ -3420,8 +3411,10 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
return RValue::get(Builder.CreateCall(F, { Src0, Src1 }));
}
case Builtin::BI__builtin_frexpl: {
- auto &Triple = getTarget().getTriple();
- if (Triple.isPPC() && Triple.isOSLinux() &&
+ // Linux PPC will not be adding additional PPCDoubleDouble support.
+ // WIP to switch default to IEEE long double. Will emit libcall for
+ // frexpl instead of legalizing this type in the BE.
+ if (getTarget().getTriple().isPPC() &&
&getTarget().getLongDoubleFormat() == &llvm::APFloat::PPCDoubleDouble())
break;
LLVM_FALLTHROUGH;
diff --git a/clang/test/CodeGen/math-builtins-long.c b/clang/test/CodeGen/math-builtins-long.c
index f3c328dcbfcd7c..ad0d2122b597fa 100644
--- a/clang/test/CodeGen/math-builtins-long.c
+++ b/clang/test/CodeGen/math-builtins-long.c
@@ -35,7 +35,7 @@ void foo(long double f, long double *l, int *i, const char *c) {
__builtin_fabsl(f);
// F80: call { x86_fp80, i32 } @llvm.frexp.f80.i32(x86_fp80 %{{.+}})
- // PPC: call { ppc_fp128, i32 } @llvm.frexp.ppcf128.i32(ppc_fp128 %{{.+}})
+ // PPC: call ppc_fp128 @frexpl(ppc_fp128 noundef %{{.+}}, ptr noundef %{{.+}})
// X86F128: call { fp128, i32 } @llvm.frexp.f128.i32(fp128 %{{.+}})
// PPCF128: call { fp128, i32 } @llvm.frexp.f128.i32(fp128 %{{.+}})
__builtin_frexpl(f,i);
>From b5dbfff5fb6b90e3da9552034c922e6baaad5b99 Mon Sep 17 00:00:00 2001
From: Lei Huang <lei at ca.ibm.com>
Date: Thu, 14 Dec 2023 11:38:59 -0600
Subject: [PATCH 3/3] fixup condition
---
clang/lib/CodeGen/CGBuiltin.cpp | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 73df0ef99f853c..3327866d2b9623 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -3414,8 +3414,7 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
// Linux PPC will not be adding additional PPCDoubleDouble support.
// WIP to switch default to IEEE long double. Will emit libcall for
// frexpl instead of legalizing this type in the BE.
- if (getTarget().getTriple().isPPC() &&
- &getTarget().getLongDoubleFormat() == &llvm::APFloat::PPCDoubleDouble())
+ if (&getTarget().getLongDoubleFormat() == &llvm::APFloat::PPCDoubleDouble())
break;
LLVM_FALLTHROUGH;
}
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