Date: Sun, 01 Jan 2012 10:24:45 -0600 From: Nathan Whitehorn <nwhitehorn@freebsd.org> To: Dimitry Andric <dim@FreeBSD.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r229169 - head/lib/clang Message-ID: <4F0088CD.5010202@freebsd.org> In-Reply-To: <4F00859C.5020205@FreeBSD.org> References: <201201011556.q01FuF5V019342@svn.freebsd.org> <4F00859C.5020205@FreeBSD.org>
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On 01/01/12 10:11, Dimitry Andric wrote: > On 2012-01-01 16:56, Nathan Whitehorn wrote: >> Author: nwhitehorn >> Date: Sun Jan 1 15:56:15 2012 >> New Revision: 229169 >> URL: http://svn.freebsd.org/changeset/base/229169 >> >> Log: >> Instead of forcing -O1 on PowerPC for LLVM and clang, fix the actual >> problem by adding -fno-strict-aliasing to CFLAGS. Since this is a >> global >> issue that just happened to manifest on PowerPC, add this to CFLAGS >> unconditionally. >> >> MFC after: 1 week >> >> Modified: >> head/lib/clang/clang.build.mk >> >> Modified: head/lib/clang/clang.build.mk >> ============================================================================== >> >> --- head/lib/clang/clang.build.mk Sun Jan 1 09:12:21 2012 >> (r229168) >> +++ head/lib/clang/clang.build.mk Sun Jan 1 15:56:15 2012 >> (r229169) >> @@ -8,10 +8,8 @@ CFLAGS+=-I${LLVM_SRCS}/include -I${CLANG >> -DLLVM_ON_UNIX -DLLVM_ON_FREEBSD \ >> -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS #-DNDEBUG >> >> -# Correct for gcc miscompilation when compiling on PPC with -O2 >> -.if ${MACHINE_CPUARCH} == "powerpc" >> -CFLAGS+= -O1 >> -.endif >> +# LLVM is not strict aliasing safe as of 12/31/2011 >> +CFLAGS+= -fno-strict-aliasing > > Actually, LLVM is strict-aliasing safe, but not for gcc 4.2.1. :) > > There is some sort of problem with gcc's optimizer that made a few LLVM > tests fails mysteriously in the past. At a certain point, these > problems went away for x86, but apparently not for non-x86... > > In any case, this option should only have to be added when the compiler > is base gcc. Ah, interesting. I'm not quite sure how to express "is compiler base GCC", but I'm guessing you have more experience there. Would you mind fixing that? -Nathan
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