vhscampos created this revision.
Herald added subscribers: cfe-commits, danielkiss, kristof.beyls.
Herald added a project: clang.
vhscampos added a child revision: D82949: [Driver][ARM] Disable bf16 when
hardware FP support is missing.
vhscampos added a reviewer: chill.
A list of target features is disabled when there is no hardware
floating-point support. This is the case when one of the following
options is passed to clang:
- -mfloat-abi=soft
- -mfpu=none
This option list is missing, however, the extension "+nofp" that can be
specified in -march flags, such as "-march=armv8-a+nofp".
This patch also disables unsupported target features when nofp is passed
to -march.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D82948
Files:
clang/lib/Driver/ToolChains/Arch/ARM.cpp
Index: clang/lib/Driver/ToolChains/Arch/ARM.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Arch/ARM.cpp
+++ clang/lib/Driver/ToolChains/Arch/ARM.cpp
@@ -285,6 +285,35 @@
(NoMVE == F.rend() || std::distance(MVE, NoMVE) > 0);
}
+static void appendNoFPUnsupportedFeatures(const arm::FloatABI ABI,
+ const unsigned FPUID,
+ const StringRef &ArchName,
+ std::vector<StringRef> &Features) {
+ auto checkFPDisabledInArchName = [](const StringRef &ArchName) {
+ SmallVector<StringRef, 8> Split;
+ ArchName.split(Split, '+', -1, false);
+ return llvm::any_of(
+ Split, [](const StringRef &Extension) { return Extension == "nofp"; });
+ };
+
+ if (ABI == arm::FloatABI::Soft) {
+ llvm::ARM::getFPUFeatures(llvm::ARM::FK_NONE, Features);
+
+ // Disable all features relating to hardware FP, not already disabled by
the
+ // above call.
+ Features.insert(Features.end(),
+ {"-dotprod", "-fp16fml", "-mve", "-mve.fp", "-fpregs"});
+ } else if (FPUID == llvm::ARM::FK_NONE ||
+ checkFPDisabledInArchName(ArchName)) {
+ // -mfpu=none or -march=armvX+nofp is *very* similar to -mfloat-abi=soft,
+ // only that it should not disable MVE-I.
+ Features.insert(Features.end(), {"-dotprod", "-fp16fml", "-mve.fp"});
+ if (!hasIntegerMVE(Features)) {
+ Features.emplace_back("-fpregs");
+ }
+ }
+}
+
void arm::getARMTargetFeatures(const Driver &D, const llvm::Triple &Triple,
const ArgList &Args, ArgStringList &CmdArgs,
std::vector<StringRef> &Features, bool ForAS) {
@@ -455,23 +484,10 @@
Features.push_back("+fullfp16");
}
- // Setting -msoft-float/-mfloat-abi=soft effectively disables the FPU (GCC
- // ignores the -mfpu options in this case).
- // Note that the ABI can also be set implicitly by the target selected.
- if (ABI == arm::FloatABI::Soft) {
- llvm::ARM::getFPUFeatures(llvm::ARM::FK_NONE, Features);
-
- // Disable all features relating to hardware FP, not already disabled by
the
- // above call.
- Features.insert(Features.end(),
- {"-dotprod", "-fp16fml", "-mve", "-mve.fp", "-fpregs"});
- } else if (FPUID == llvm::ARM::FK_NONE) {
- // -mfpu=none is *very* similar to -mfloat-abi=soft, only that it should
not
- // disable MVE-I.
- Features.insert(Features.end(), {"-dotprod", "-fp16fml", "-mve.fp"});
- if (!hasIntegerMVE(Features))
- Features.emplace_back("-fpregs");
- }
+ // Setting -msoft-float/-mfloat-abi=soft, -mfpu=none, or adding +nofp to
+ // -march effectively disables the FPU (GCC ignores the -mfpu options in this
+ // case). Note that the ABI can also be set implicitly by the target
selected.
+ appendNoFPUnsupportedFeatures(ABI, FPUID, ArchName, Features);
// En/disable crc code generation.
if (Arg *A = Args.getLastArg(options::OPT_mcrc, options::OPT_mnocrc)) {
Index: clang/lib/Driver/ToolChains/Arch/ARM.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Arch/ARM.cpp
+++ clang/lib/Driver/ToolChains/Arch/ARM.cpp
@@ -285,6 +285,35 @@
(NoMVE == F.rend() || std::distance(MVE, NoMVE) > 0);
}
+static void appendNoFPUnsupportedFeatures(const arm::FloatABI ABI,
+ const unsigned FPUID,
+ const StringRef &ArchName,
+ std::vector<StringRef> &Features) {
+ auto checkFPDisabledInArchName = [](const StringRef &ArchName) {
+ SmallVector<StringRef, 8> Split;
+ ArchName.split(Split, '+', -1, false);
+ return llvm::any_of(
+ Split, [](const StringRef &Extension) { return Extension == "nofp"; });
+ };
+
+ if (ABI == arm::FloatABI::Soft) {
+ llvm::ARM::getFPUFeatures(llvm::ARM::FK_NONE, Features);
+
+ // Disable all features relating to hardware FP, not already disabled by the
+ // above call.
+ Features.insert(Features.end(),
+ {"-dotprod", "-fp16fml", "-mve", "-mve.fp", "-fpregs"});
+ } else if (FPUID == llvm::ARM::FK_NONE ||
+ checkFPDisabledInArchName(ArchName)) {
+ // -mfpu=none or -march=armvX+nofp is *very* similar to -mfloat-abi=soft,
+ // only that it should not disable MVE-I.
+ Features.insert(Features.end(), {"-dotprod", "-fp16fml", "-mve.fp"});
+ if (!hasIntegerMVE(Features)) {
+ Features.emplace_back("-fpregs");
+ }
+ }
+}
+
void arm::getARMTargetFeatures(const Driver &D, const llvm::Triple &Triple,
const ArgList &Args, ArgStringList &CmdArgs,
std::vector<StringRef> &Features, bool ForAS) {
@@ -455,23 +484,10 @@
Features.push_back("+fullfp16");
}
- // Setting -msoft-float/-mfloat-abi=soft effectively disables the FPU (GCC
- // ignores the -mfpu options in this case).
- // Note that the ABI can also be set implicitly by the target selected.
- if (ABI == arm::FloatABI::Soft) {
- llvm::ARM::getFPUFeatures(llvm::ARM::FK_NONE, Features);
-
- // Disable all features relating to hardware FP, not already disabled by the
- // above call.
- Features.insert(Features.end(),
- {"-dotprod", "-fp16fml", "-mve", "-mve.fp", "-fpregs"});
- } else if (FPUID == llvm::ARM::FK_NONE) {
- // -mfpu=none is *very* similar to -mfloat-abi=soft, only that it should not
- // disable MVE-I.
- Features.insert(Features.end(), {"-dotprod", "-fp16fml", "-mve.fp"});
- if (!hasIntegerMVE(Features))
- Features.emplace_back("-fpregs");
- }
+ // Setting -msoft-float/-mfloat-abi=soft, -mfpu=none, or adding +nofp to
+ // -march effectively disables the FPU (GCC ignores the -mfpu options in this
+ // case). Note that the ABI can also be set implicitly by the target selected.
+ appendNoFPUnsupportedFeatures(ABI, FPUID, ArchName, Features);
// En/disable crc code generation.
if (Arg *A = Args.getLastArg(options::OPT_mcrc, options::OPT_mnocrc)) {
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