[clang][Driver][ARM] Favor -mfpu over default CPU features

When processing the command line options march, mcpu and mfpu, we store
the implied target features on a vector. The change D62998 introduced a
temporary vector, where the processed features get accumulated. When
calling DecodeARMFeaturesFromCPU, which sets the default features for
the specified CPU, we certainly don't want to override the features
that have been explicitly specified on the command line. Therefore, the
default features should appear first in the final vector. This problem
became evident once I added the missing (unhandled) target features in
ARM::getExtensionFeatures.

Differential Revision: https://reviews.llvm.org/D63936

llvm-svn: 366027

clang/lib/Driver/ToolChains/Arch/ARM.cpp

@@ -376,7 +376,11 @@ void arm::getARMTargetFeatures(const ToolChain &TC,
         Features.push_back(
             Args.MakeArgString((F.second ? "+" : "-") + F.first()));
   } else if (!CPUName.empty()) {
-    DecodeARMFeaturesFromCPU(D, CPUName, ExtensionFeatures);
+    // This sets the default features for the specified CPU. We certainly don't
+    // want to override the features that have been explicitly specified on the
+    // command line. Therefore, process them directly instead of appending them
+    // at the end later.
+    DecodeARMFeaturesFromCPU(D, CPUName, Features);
   }
 
   if (CPUArg)

clang/test/CodeGen/arm-target-features.c

@@ -32,7 +32,7 @@
 
 // RUN: %clang_cc1 -triple thumbv8-linux-gnueabihf -target-cpu exynos-m4 -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK-BASIC-V82
 // RUN: %clang_cc1 -triple thumbv8-linux-gnueabihf -target-cpu exynos-m5 -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK-BASIC-V82
-// CHECK-BASIC-V82: "target-features"="+armv8.2-a,+crc,+crypto,+d32,+dotprod,+dsp,+fp-armv8,+fp-armv8d16,+fp-armv8d16sp,+fp-armv8sp,+fp16,+fp64,+fpregs,+hwdiv,+hwdiv-arm,+neon,+ras,+thumb-mode,+vfp2,+vfp2d16,+vfp2d16sp,+vfp2sp,+vfp3,+vfp3d16,+vfp3d16sp,+vfp3sp,+vfp4,+vfp4d16,+vfp4d16sp,+vfp4sp"
+// CHECK-BASIC-V82: "target-features"="+armv8.2-a,+crc,+crypto,+d32,+dotprod,+dsp,+fp-armv8,+fp-armv8d16,+fp-armv8d16sp,+fp-armv8sp,+fp16,+fp64,+fpregs,+fullfp16,+hwdiv,+hwdiv-arm,+neon,+ras,+thumb-mode,+vfp2,+vfp2d16,+vfp2d16sp,+vfp2sp,+vfp3,+vfp3d16,+vfp3d16sp,+vfp3sp,+vfp4,+vfp4d16,+vfp4d16sp,+vfp4sp"
 
 // RUN: %clang_cc1 -triple armv8-linux-gnueabi -target-cpu cortex-a53 -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK-BASIC-V8-ARM
 // CHECK-BASIC-V8-ARM: "target-features"="+armv8-a,+crc,+crypto,+d32,+dsp,+fp-armv8,+fp-armv8d16,+fp-armv8d16sp,+fp-armv8sp,+fp16,+fp64,+fpregs,+hwdiv,+hwdiv-arm,+neon,+vfp2,+vfp2d16,+vfp2d16sp,+vfp2sp,+vfp3,+vfp3d16,+vfp3d16sp,+vfp3sp,+vfp4,+vfp4d16,+vfp4d16sp,+vfp4sp,-thumb-mode"

llvm/include/llvm/Support/ARMTargetParser.def

@@ -148,6 +148,7 @@ ARM_ARCH_EXT_NAME("aes",      ARM::AEK_AES,      "+aes",   "-aes")
 ARM_ARCH_EXT_NAME("dotprod",  ARM::AEK_DOTPROD,  "+dotprod","-dotprod")
 ARM_ARCH_EXT_NAME("dsp",      ARM::AEK_DSP,      "+dsp",   "-dsp")
 ARM_ARCH_EXT_NAME("fp",       ARM::AEK_FP,       nullptr,  nullptr)
+ARM_ARCH_EXT_NAME("fp.dp",    ARM::AEK_FP_DP,    nullptr,  nullptr)
 ARM_ARCH_EXT_NAME("mve",      ARM::AEK_SIMD,     "+mve",   "-mve")
 ARM_ARCH_EXT_NAME("mve.fp",   (ARM::AEK_SIMD | ARM::AEK_FP), "+mve.fp", "-mve.fp")
 ARM_ARCH_EXT_NAME("idiv",     (ARM::AEK_HWDIVARM | ARM::AEK_HWDIVTHUMB), nullptr, nullptr)

llvm/lib/Support/ARMTargetParser.cpp

@@ -409,30 +409,12 @@ bool ARM::getExtensionFeatures(unsigned Extensions,
   if (Extensions == AEK_INVALID)
     return false;
 
-  if (Extensions & AEK_CRC)
-    Features.push_back("+crc");
-  else
-    Features.push_back("-crc");
-
-  if (Extensions & AEK_DSP)
-    Features.push_back("+dsp");
-  else
-    Features.push_back("-dsp");
-
-  if (Extensions & AEK_FP16FML)
-    Features.push_back("+fp16fml");
-  else
-    Features.push_back("-fp16fml");
-
-  if (Extensions & AEK_RAS)
-    Features.push_back("+ras");
-  else
-    Features.push_back("-ras");
-
-  if (Extensions & AEK_DOTPROD)
-    Features.push_back("+dotprod");
-  else
-    Features.push_back("-dotprod");
+  for (const auto AE : ARCHExtNames) {
+    if ((Extensions & AE.ID) == AE.ID && AE.Feature)
+      Features.push_back(AE.Feature);
+    else if (AE.NegFeature)
+      Features.push_back(AE.NegFeature);
+  }
 
   return getHWDivFeatures(Extensions, Features);
 }

llvm/unittests/Support/TargetParserTest.cpp

@@ -571,17 +571,18 @@ TEST(TargetParserTest, ARMFPURestriction) {
 TEST(TargetParserTest, ARMExtensionFeatures) {
   std::map<unsigned, std::vector<StringRef>> Extensions;
 
-  Extensions[ARM::AEK_CRC]        = { "+crc",       "-crc" };
-  Extensions[ARM::AEK_DSP]        = { "+dsp",       "-dsp" };
+  for (auto &Ext : ARM::ARCHExtNames) {
+    if (Ext.Feature && Ext.NegFeature)
+      Extensions[Ext.ID] = { StringRef(Ext.Feature),
+                             StringRef(Ext.NegFeature) };
+  }
+
   Extensions[ARM::AEK_HWDIVARM]   = { "+hwdiv-arm", "-hwdiv-arm" };
   Extensions[ARM::AEK_HWDIVTHUMB] = { "+hwdiv",     "-hwdiv" };
-  Extensions[ARM::AEK_RAS]        = { "+ras",       "-ras" };
-  Extensions[ARM::AEK_FP16FML]    = { "+fp16fml",   "-fp16fml" };
-  Extensions[ARM::AEK_DOTPROD]    = { "+dotprod",   "-dotprod" };
 
   std::vector<StringRef> Features;
 
-  EXPECT_FALSE(AArch64::getExtensionFeatures(ARM::AEK_INVALID, Features));
+  EXPECT_FALSE(ARM::getExtensionFeatures(ARM::AEK_INVALID, Features));
 
   for (auto &E : Extensions) {
     // test +extension
@@ -598,7 +599,7 @@ TEST(TargetParserTest, ARMExtensionFeatures) {
     Found = std::find(std::begin(Features), std::end(Features), E.second.at(1));
     EXPECT_TRUE(Found != std::end(Features));
     EXPECT_TRUE(Extensions.size() == Features.size());
-   }
+  }
 }
 
 TEST(TargetParserTest, ARMFPUFeatures) {