r214148 - Fix up handling of ARM options for controlling strict alignment.
Bob Wilson
bob.wilson at apple.com
Mon Jul 28 17:23:18 PDT 2014
Author: bwilson
Date: Mon Jul 28 19:23:18 2014
New Revision: 214148
URL: http://llvm.org/viewvc/llvm-project?rev=214148&view=rev
Log:
Fix up handling of ARM options for controlling strict alignment.
The -mstrict-align option was originally added in r167619 as a target-
independent option. It was then changed in r167623 to be implemented with an
ARM-specific backend option, even though the code remained in the
target-independent Clang::ConstructJob function. This means that if you used
the -mstrict-align option with a non-ARM target, you would still get the
-arm-strict-align option getting passed to the backend, which was harmless
but gross. The driver option was then replaced by the GCC-compatible
-m[no-]unaligned-access option (r189175) and modified to work with AArch64
(r208075). However, in the process, the help text for -mstrict-align was
incorrectly changed to show it as only being supported for AArch64. Even worse,
the logic for handling these options together with -mkernel was wrong for
AArch64, where -mkernel does not currently imply strict alignment.
This patch fixes up all of those things. Besides the obvious change to the
option help text, it moves the logic into the ARM and AArch64-specific parts
of the driver, so that the option will be correctly ignored for non-ARM
targets. <rdar://problem/17823697>
Modified:
cfe/trunk/include/clang/Driver/Options.td
cfe/trunk/lib/Driver/Tools.cpp
cfe/trunk/test/Driver/arm-alignment.c
Modified: cfe/trunk/include/clang/Driver/Options.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/Options.td?rev=214148&r1=214147&r2=214148&view=diff
==============================================================================
--- cfe/trunk/include/clang/Driver/Options.td (original)
+++ cfe/trunk/include/clang/Driver/Options.td Mon Jul 28 19:23:18 2014
@@ -1113,7 +1113,7 @@ def munaligned_access : Flag<["-"], "mun
def mno_unaligned_access : Flag<["-"], "mno-unaligned-access">, Group<m_arm_Features_Group>,
HelpText<"Force all memory accesses to be aligned (AArch32/AArch64 only)">;
def mstrict_align : Flag<["-"], "mstrict-align">, Alias<mno_unaligned_access>, Flags<[CC1Option,HelpHidden]>,
- HelpText<"Force all memory accesses to be aligned (AArch64 only, same as mno-unaligned-access)">;
+ HelpText<"Force all memory accesses to be aligned (same as mno-unaligned-access)">;
def mno_thumb : Flag<["-"], "mno-thumb">, Group<m_arm_Features_Group>;
def mrestrict_it: Flag<["-"], "mrestrict-it">, Group<m_arm_Features_Group>,
HelpText<"Disallow generation of deprecated IT blocks for ARMv8. It is on by default for ARMv8 Thumb mode.">;
Modified: cfe/trunk/lib/Driver/Tools.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=214148&r1=214147&r2=214148&view=diff
==============================================================================
--- cfe/trunk/lib/Driver/Tools.cpp (original)
+++ cfe/trunk/lib/Driver/Tools.cpp Mon Jul 28 19:23:18 2014
@@ -799,6 +799,18 @@ void Clang::AddARMTargetArgs(const ArgLi
CmdArgs.push_back("-arm-use-movt=0");
}
+ // -mkernel implies -mstrict-align; don't add the redundant option.
+ if (!KernelOrKext) {
+ if (Arg *A = Args.getLastArg(options::OPT_mno_unaligned_access,
+ options::OPT_munaligned_access)) {
+ CmdArgs.push_back("-backend-option");
+ if (A->getOption().matches(options::OPT_mno_unaligned_access))
+ CmdArgs.push_back("-arm-strict-align");
+ else
+ CmdArgs.push_back("-arm-no-strict-align");
+ }
+ }
+
// Setting -mno-global-merge disables the codegen global merge pass. Setting
// -mglobal-merge has no effect as the pass is enabled by default.
if (Arg *A = Args.getLastArg(options::OPT_mglobal_merge,
@@ -873,9 +885,13 @@ void Clang::AddAArch64TargetArgs(const A
CmdArgs.push_back("-target-abi");
CmdArgs.push_back(ABIName);
- if (Args.hasArg(options::OPT_mstrict_align)) {
+ if (Arg *A = Args.getLastArg(options::OPT_mno_unaligned_access,
+ options::OPT_munaligned_access)) {
CmdArgs.push_back("-backend-option");
- CmdArgs.push_back("-aarch64-strict-align");
+ if (A->getOption().matches(options::OPT_mno_unaligned_access))
+ CmdArgs.push_back("-aarch64-strict-align");
+ else
+ CmdArgs.push_back("-aarch64-no-strict-align");
}
// Setting -mno-global-merge disables the codegen global merge pass. Setting
@@ -3673,27 +3689,6 @@ void Clang::ConstructJob(Compilation &C,
StringRef alignment = Args.getLastArgValue(options::OPT_mstack_alignment);
CmdArgs.push_back(Args.MakeArgString("-mstack-alignment=" + alignment));
}
- // -mkernel implies -mstrict-align; don't add the redundant option.
- if (!KernelOrKext) {
- if (Arg *A = Args.getLastArg(options::OPT_mno_unaligned_access,
- options::OPT_munaligned_access)) {
- if (A->getOption().matches(options::OPT_mno_unaligned_access)) {
- CmdArgs.push_back("-backend-option");
- if (getToolChain().getTriple().getArch() == llvm::Triple::aarch64 ||
- getToolChain().getTriple().getArch() == llvm::Triple::aarch64_be)
- CmdArgs.push_back("-aarch64-strict-align");
- else
- CmdArgs.push_back("-arm-strict-align");
- } else {
- CmdArgs.push_back("-backend-option");
- if (getToolChain().getTriple().getArch() == llvm::Triple::aarch64 ||
- getToolChain().getTriple().getArch() == llvm::Triple::aarch64_be)
- CmdArgs.push_back("-aarch64-no-strict-align");
- else
- CmdArgs.push_back("-arm-no-strict-align");
- }
- }
- }
if (Arg *A = Args.getLastArg(options::OPT_mrestrict_it,
options::OPT_mno_restrict_it)) {
Modified: cfe/trunk/test/Driver/arm-alignment.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/arm-alignment.c?rev=214148&r1=214147&r2=214148&view=diff
==============================================================================
--- cfe/trunk/test/Driver/arm-alignment.c (original)
+++ cfe/trunk/test/Driver/arm-alignment.c Mon Jul 28 19:23:18 2014
@@ -44,5 +44,8 @@
// RUN: %clang -target aarch64-none-gnueabi -munaligned-access -mstrict-align -### %s 2> %t
// RUN: FileCheck --check-prefix=CHECK-ALIGNED-AARCH64 < %t %s
+// RUN: %clang -target aarch64-none-gnueabi -mkernel -mno-unaligned-access -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-ALIGNED-AARCH64 < %t %s
+
// CHECK-ALIGNED-ARM: "-backend-option" "-arm-strict-align"
// CHECK-ALIGNED-AARCH64: "-backend-option" "-aarch64-strict-align"
More information about the cfe-commits
mailing list