From f4d3f7a0b9dc5a7bbb3e33cc0088c3404e69326b Mon Sep 17 00:00:00 2001 From: Nick Lewycky Date: Tue, 6 Dec 2011 03:33:03 +0000 Subject: [PATCH] Stack realignment is a tristate. Add -mno-stackrealign to turn off all stack realignment, even with locals with alignment exceeding the ABI guarantee. llvm-svn: 145909 --- clang/include/clang/Driver/Options.td | 1 + clang/include/clang/Frontend/CodeGenOptions.h | 4 ++-- clang/lib/CodeGen/BackendUtil.cpp | 7 ++----- clang/lib/Driver/Tools.cpp | 13 +++++++++++-- clang/lib/Frontend/CompilerInvocation.cpp | 2 +- clang/test/Driver/stackrealign.c | 12 ++++++++++++ 6 files changed, 29 insertions(+), 10 deletions(-) create mode 100644 clang/test/Driver/stackrealign.c diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index b4f04b636469..8cdf70094359 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -583,6 +583,7 @@ def mno_red_zone : Flag<"-mno-red-zone">, Group; def mno_relax_all : Flag<"-mno-relax-all">, Group; def mno_rtd: Flag<"-mno-rtd">, Group; def mno_soft_float : Flag<"-mno-soft-float">, Group; +def mno_stackrealign : Flag<"-mno-stackrealign">, Group; def mno_sse2 : Flag<"-mno-sse2">, Group; def mno_sse3 : Flag<"-mno-sse3">, Group; def mno_sse4a : Flag<"-mno-sse4a">, Group; diff --git a/clang/include/clang/Frontend/CodeGenOptions.h b/clang/include/clang/Frontend/CodeGenOptions.h index 091246703cc9..f15125e01617 100644 --- a/clang/include/clang/Frontend/CodeGenOptions.h +++ b/clang/include/clang/Frontend/CodeGenOptions.h @@ -105,8 +105,8 @@ public: unsigned VerifyModule : 1; /// Control whether the module should be run /// through the LLVM Verifier. - unsigned RealignStack : 1; /// Controls whether stack frame should be - /// readjusted to the desired alignment. + unsigned StackRealignment : 1; /// Control whether to permit stack + /// realignment. unsigned StackAlignment; /// Overrides default stack alignment, /// if not 0. diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp index 3bc57e767c3b..5ef72d486e57 100644 --- a/clang/lib/CodeGen/BackendUtil.cpp +++ b/clang/lib/CodeGen/BackendUtil.cpp @@ -289,11 +289,6 @@ bool EmitAssemblyHelper::AddEmitPasses(BackendAction Action, llvm::TargetOptions Options; - if (CodeGenOpts.RealignStack) - Options.RealignStack = true; - if (CodeGenOpts.StackAlignment) - Options.StackAlignmentOverride = CodeGenOpts.StackAlignment; - // Set frame pointer elimination mode. if (!CodeGenOpts.DisableFPElim) { Options.NoFramePointerElim = false; @@ -322,6 +317,8 @@ bool EmitAssemblyHelper::AddEmitPasses(BackendAction Action, Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS; Options.UnsafeFPMath = CodeGenOpts.UnsafeFPMath; Options.UseSoftFloat = CodeGenOpts.SoftFloat; + Options.StackAlignmentOverride = CodeGenOpts.StackAlignment; + Options.RealignStack = CodeGenOpts.StackRealignment; TargetMachine *TM = TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr, Options, diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp index 074be43fdb4a..4987b0a81f05 100644 --- a/clang/lib/Driver/Tools.cpp +++ b/clang/lib/Driver/Tools.cpp @@ -1796,8 +1796,17 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA, CmdArgs.push_back(Args.MakeArgString(Twine(StackProtectorLevel))); } - if (Args.hasArg(options::OPT_mstackrealign)) - CmdArgs.push_back("-mstackrealign"); + // Translate -mstackrealign + if (Args.hasFlag(options::OPT_mstackrealign, options::OPT_mno_stackrealign, + false)) { + CmdArgs.push_back("-backend-option"); + CmdArgs.push_back("-force-align-stack"); + } + if (!Args.hasFlag(options::OPT_mno_stackrealign, options::OPT_mstackrealign, + false)) { + CmdArgs.push_back(Args.MakeArgString("-mstackrealign")); + } + if (Args.hasArg(options::OPT_mstack_alignment)) { StringRef alignment = Args.getLastArgValue(options::OPT_mstack_alignment); CmdArgs.push_back(Args.MakeArgString("-mstack-alignment=" + alignment)); diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp index b89bf0808c94..2de9e8068c7a 100644 --- a/clang/lib/Frontend/CompilerInvocation.cpp +++ b/clang/lib/Frontend/CompilerInvocation.cpp @@ -1114,7 +1114,7 @@ static void ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK, Opts.CoverageFile = Args.getLastArgValue(OPT_coverage_file); Opts.DebugCompilationDir = Args.getLastArgValue(OPT_fdebug_compilation_dir); Opts.LinkBitcodeFile = Args.getLastArgValue(OPT_mlink_bitcode_file); - Opts.RealignStack = Args.hasArg(OPT_mstackrealign); + Opts.StackRealignment = Args.hasArg(OPT_mstackrealign); if (Arg *A = Args.getLastArg(OPT_mstack_alignment)) { StringRef Val = A->getValue(Args); Val.getAsInteger(10, Opts.StackAlignment); diff --git a/clang/test/Driver/stackrealign.c b/clang/test/Driver/stackrealign.c new file mode 100644 index 000000000000..c5221d652422 --- /dev/null +++ b/clang/test/Driver/stackrealign.c @@ -0,0 +1,12 @@ +// RUN: %clang -### %s 2>&1 | FileCheck %s -check-prefix=NORMAL +// NORMAL-NOT: -force-align-stack +// NORMAL: -mstackrealign + +// RUN: %clang -### -mstackrealign %s 2>&1 | FileCheck %s -check-prefix=MREALIGN +// MREALIGN: -force-align-stack +// MREALIGN: -mstackrealign + +// RUN: %clang -### -mno-stackrealign %s 2>&1 | \ +// RUN: FileCheck %s -check-prefix=MNOREALIGN +// MNOREALIGN-NOT: -force-align-stack +// MNOREALIGN-NOT: -mstackrealign