Allow case-insensitive values for -mcpu for ARM in line with GCC.

[enefaim]

Summary

GCC allows case-insensitive values for -mcpu, -march and -mtune options.
This patch implements the same behaviour for the -mcpu option.

This is a new version of r236859, which has been reverted due to test failures
in the AArch64 code path when running on 32 ARM buildbot.
I separated the ARM code path into this patch, while debugging the AArch64 failures.

[richard.barton.arm]

My only observation is that you have changed the Krait codepath, but have not added a test for that.

Otherwise LGTM.

[craig.topper]

+ StringRef MCPU = StringRef(A->getValue()).lower();

lower returns an std::string which will be immediately deleted leaving the
MCPU StringRef pointing at stale memory. MCPU should be a std::string.

[rengolin]

I agree a test for krait is needed.

cheers,
--renato

lib/Driver/Tools.cpp

5755

Voicing Craig Topper's comment on the list:

"lower returns an std::string which will be immediately deleted leaving the MCPU StringRef pointing at stale memory. MCPU should be a std::string"

[enefaim]

Changes in this version:

• Added test cases for krait
• Switched getARMTargetCPU to use std::string instead of StringRef

[rengolin]

lib/Driver/Tools.cpp

5750

Don't you need to change the type in the callers, too? Otherwise, the StringRef will refer to a temp variable that may disappear until it's used.

test/Driver/krait-cpu.c

8 ↗

(On Diff #26972)

You don't need a new CHECK line type, you could have re-used CHECK-CPUV7A

[enefaim]

Changes in this version:

• Change StringRef to std::string in getARMTargetCPU callers to avoid possible memory corruptions.
• Remove unnecessary CHECK line from test/Driver/krait-cpu.c.

[rengolin]

LGTM, Thanks!

[rengolin]

r239059

lib/Driver/Tools.cpp

   const char *result = Triple.getARMCPUForArch(MArch);
   if (result)
     return result;
   else
     return "";
 }
 
 /// getARMTargetCPU - Get the (LLVM) name of the ARM cpu we are targeting.
 StringRef arm::getARMTargetCPU(const ArgList &Args,
                                const llvm::Triple &Triple) {
   // FIXME: Warn on inconsistent use of -mcpu and -march.
   // If we have -mcpu=, use that.
   if (Arg *A = Args.getLastArg(options::OPT_mcpu_EQ)) {
-    StringRef MCPU = A->getValue();
+    StringRef MCPU = StringRef(A->getValue()).lower();
     // Handle -mcpu=native.
     if (MCPU == "native")
       return llvm::sys::getHostCPUName();
     else
       return MCPU;
   }
 
   return getARMCPUForMArch(Args, Triple);

 
     Args.AddLastArg(CmdArgs, options::OPT_march_EQ);
 
     // FIXME: remove krait check when GNU tools support krait cpu
     // for now replace it with -march=armv7-a  to avoid a lower
     // march from being picked in the absence of a cpu flag.
     Arg *A;
     if ((A = Args.getLastArg(options::OPT_mcpu_EQ)) &&
-      StringRef(A->getValue()) == "krait")
+      StringRef(A->getValue()).lower() == "krait")
         CmdArgs.push_back("-march=armv7-a");
     else
       Args.AddLastArg(CmdArgs, options::OPT_mcpu_EQ);
     Args.AddLastArg(CmdArgs, options::OPT_mfpu_EQ);
     break;
   }
   case llvm::Triple::mips:
   case llvm::Triple::mipsel:

test/Driver/arm-cortex-cpus.c

 
 // RUN: %clang -target armeb -mcpu=cortex-a53 -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A-THUMB %s
 // RUN: %clang -target armeb -mcpu=cortex-a57 -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A-THUMB %s
 // RUN: %clang -target armeb -mcpu=cortex-a72 -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A-THUMB %s
 // RUN: %clang -target arm -mcpu=cortex-a53 -mbig-endian -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A-THUMB %s
 // RUN: %clang -target arm -mcpu=cortex-a57 -mbig-endian -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A-THUMB %s
 // RUN: %clang -target arm -mcpu=cortex-a72 -mbig-endian -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A-THUMB %s
 // CHECK-BE-CPUV8A-THUMB: "-cc1"{{.*}} "-triple" "thumbebv8-{{.*}}
+
+// ================== Check whether -mcpu accepts mixed-case values.
+// RUN: %clang -target arm-linux-gnueabi -mcpu=Cortex-a5 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CASE-INSENSITIVE-CPUV7A %s
+// RUN: %clang -target arm-linux-gnueabi -mcpu=cortex-A7 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CASE-INSENSITIVE-CPUV7A %s
+// RUN: %clang -target arm-linux-gnueabi -mcpu=CORTEX-a8 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CASE-INSENSITIVE-CPUV7A %s
+// RUN: %clang -target arm-linux-gnueabi -mcpu=Cortex-A9 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CASE-INSENSITIVE-CPUV7A %s
+// RUN: %clang -target arm-linux-gnueabi -mcpu=corteX-A12 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CASE-INSENSITIVE-CPUV7A %s
+// RUN: %clang -target arm-linux-gnueabi -mcpu=CorteX-a15 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CASE-INSENSITIVE-CPUV7A %s
+// RUN: %clang -target arm-linux-gnueabi -mcpu=CorteX-A17 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CASE-INSENSITIVE-CPUV7A %s
+// CHECK-CASE-INSENSITIVE-CPUV7A: "-cc1"{{.*}} "-triple" "armv7-{{.*}}