Pull in r148240 from upstream llvm trunk:

Make sure the non-SSE lowering for fences correctly clobbers EFLAGS.
  PR11768.

In particular, this fixes segfaults during the build of devel/icu on
i386.  The __sync_synchronize() builtin used for implementing icu's
internal barrier could lead to incorrect behaviour.

MFC after:	3 days

This commit is contained in:

Dimitry Andric

2012-01-20 19:18:11 +00:00

parent 475cc570f4

commit 462386c6b1

1 changed files with 1 additions and 1 deletions

									
										contrib/llvm/lib/Target/X86/X86InstrCompiler.td
									
		+1
		-1
	
												View File
												
				@@ -533,7 +533,7 @@ def ATOMSWAP6432 : I<0, Pseudo, (outs GR32:$dst1, GR32:$dst2),

				// Memory barriers

				// TODO: Get this to fold the constant into the instruction.

				let isCodeGenOnly = 1 in

				let isCodeGenOnly = 1, Defs = [EFLAGS] in

				def OR32mrLocked  : I<0x09, MRMDestMem, (outs), (ins i32mem:$dst, GR32:$zero),

				                      "lock\n\t"

				                      "or{l}\t{$zero, $dst|$dst, $zero}",