Author: compnerd Date: Fri Oct 2 22:39:28 2015 New Revision: 249227 URL: http://llvm.org/viewvc/llvm-project?rev=249227&view=rev Log: Driver: follow WoA ABI recommendations
The Windows on ARM ABI recommends that FPO be disabled. This is since the Windows on ARM ABI uses the FP for fast stack walking. By paying the slight cost of the loss of registers, a much faster backtrace is possible by using the frame pointer since the pdata need not be consulted. Furthermore, even if pdata is not available, you can still more easily reconstruct the stack. Added: cfe/trunk/test/Driver/woa-fp.c Modified: cfe/trunk/lib/Driver/Tools.cpp Modified: cfe/trunk/lib/Driver/Tools.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=249227&r1=249226&r2=249227&view=diff ============================================================================== --- cfe/trunk/lib/Driver/Tools.cpp (original) +++ cfe/trunk/lib/Driver/Tools.cpp Fri Oct 2 22:39:28 2015 @@ -2655,6 +2655,10 @@ static bool shouldUseFramePointerForTarg switch (Triple.getArch()) { case llvm::Triple::x86: return !areOptimizationsEnabled(Args); + case llvm::Triple::arm: + case llvm::Triple::thumb: + // Windows on ARM builds with FPO disabled to aid fast stack walking + return true; default: // All other supported Windows ISAs use xdata unwind information, so frame // pointers are not generally useful. Added: cfe/trunk/test/Driver/woa-fp.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/woa-fp.c?rev=249227&view=auto ============================================================================== --- cfe/trunk/test/Driver/woa-fp.c (added) +++ cfe/trunk/test/Driver/woa-fp.c Fri Oct 2 22:39:28 2015 @@ -0,0 +1,40 @@ +// RUN: %clang -target armv7-windows-msvc -### -S %s -O0 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-DEFAULT +// RUN: %clang -target armv7-windows-msvc -### -S %s -O1 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-DEFAULT +// RUN: %clang -target armv7-windows-msvc -### -S %s -O2 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-DEFAULT +// RUN: %clang -target armv7-windows-msvc -### -S %s -O3 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-DEFAULT +// RUN: %clang -target armv7-windows-msvc -### -S %s -Os -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-DEFAULT + +// RUN: %clang -target armv7-windows-itanium -### -S %s -O0 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-DEFAULT +// RUN: %clang -target armv7-windows-itanium -### -S %s -O1 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-DEFAULT +// RUN: %clang -target armv7-windows-itanium -### -S %s -O2 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-DEFAULT +// RUN: %clang -target armv7-windows-itanium -### -S %s -O3 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-DEFAULT +// RUN: %clang -target armv7-windows-itanium -### -S %s -Os -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-DEFAULT + +// RUN: %clang -target armv7-windows-msvc -fomit-frame-pointer -### -S %s -O0 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-FPO +// RUN: %clang -target armv7-windows-msvc -fomit-frame-pointer -### -S %s -O1 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-FPO +// RUN: %clang -target armv7-windows-msvc -fomit-frame-pointer -### -S %s -O2 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-FPO +// RUN: %clang -target armv7-windows-msvc -fomit-frame-pointer -### -S %s -O3 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-FPO +// RUN: %clang -target armv7-windows-msvc -fomit-frame-pointer -### -S %s -Os -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-FPO + +// RUN: %clang -target armv7-windows-itanium -fomit-frame-pointer -### -S %s -O0 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-FPO +// RUN: %clang -target armv7-windows-itanium -fomit-frame-pointer -### -S %s -O1 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-FPO +// RUN: %clang -target armv7-windows-itanium -fomit-frame-pointer -### -S %s -O2 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-FPO +// RUN: %clang -target armv7-windows-itanium -fomit-frame-pointer -### -S %s -O3 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-FPO +// RUN: %clang -target armv7-windows-itanium -fomit-frame-pointer -### -S %s -Os -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-FPO + +// RUN: %clang -target armv7-windows-msvc -fno-omit-frame-pointer -### -S %s -O0 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-NO-FPO +// RUN: %clang -target armv7-windows-msvc -fno-omit-frame-pointer -### -S %s -O1 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-NO-FPO +// RUN: %clang -target armv7-windows-msvc -fno-omit-frame-pointer -### -S %s -O2 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-NO-FPO +// RUN: %clang -target armv7-windows-msvc -fno-omit-frame-pointer -### -S %s -O3 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-NO-FPO +// RUN: %clang -target armv7-windows-msvc -fno-omit-frame-pointer -### -S %s -Os -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-NO-FPO + +// RUN: %clang -target armv7-windows-itanium -fno-omit-frame-pointer -### -S %s -O0 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-NO-FPO +// RUN: %clang -target armv7-windows-itanium -fno-omit-frame-pointer -### -S %s -O1 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-NO-FPO +// RUN: %clang -target armv7-windows-itanium -fno-omit-frame-pointer -### -S %s -O2 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-NO-FPO +// RUN: %clang -target armv7-windows-itanium -fno-omit-frame-pointer -### -S %s -O3 -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-NO-FPO +// RUN: %clang -target armv7-windows-itanium -fno-omit-frame-pointer -### -S %s -Os -o /dev/null 2>&1 | FileCheck %s -check-prefix CHECK-NO-FPO + +// CHECK-DEFAULT: "-mdisable-fp-elim" +// CHECK-FPO-NOT: "-mdisable-fp-elim" +// CHECK-NO-FPO: "-mdisable-fp-elim" + _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits