llvm-project

Commit Graph

Author	SHA1	Message	Date
Manman Ren	1acb6707cd	X86: when we are auto-detecting the subtarget features, make sure we turn on FeatureFastUAMem for Nehalem, Westmere and Sandy Bridge. FeatureFastUAMem is already on if we pass in nehalem or westmere as a command argument. rdar: 7252306 llvm-svn: 161717	2012-08-10 23:43:32 +00:00
Bill Wendling	b34639de75	Filecheck-ize. llvm-svn: 140904	2011-09-30 23:40:29 +00:00
Bill Wendling	9925f197cc	When inferring the pointer alignment, if the global doesn't have an initializer and the alignment is 0 (i.e., it's defined globally in one file and declared in another file) it could get an alignment which is larger than the ABI allows for that type, resulting in aligned moves being used for unaligned loads. For instance, in file A.c: struct S s; In file B.c: struct { // something long }; extern S s; void foo() { struct S p = s; // ... } this copy is a 'memcpy' which is turned into a series of 'movaps' instructions on X86. But this is wrong, because 'struct S' has alignment of 4, not 16. llvm-svn: 140902	2011-09-30 23:19:55 +00:00

Author

SHA1

Message

Date

Manman Ren

1acb6707cd

X86: when we are auto-detecting the subtarget features, make sure we turn on

FeatureFastUAMem for Nehalem, Westmere and Sandy Bridge.

FeatureFastUAMem is already on if we pass in nehalem or westmere as a command
argument.

rdar: 7252306
llvm-svn: 161717

2012-08-10 23:43:32 +00:00

Bill Wendling

b34639de75

Filecheck-ize.

llvm-svn: 140904

2011-09-30 23:40:29 +00:00

Bill Wendling

9925f197cc

When inferring the pointer alignment, if the global doesn't have an initializer

and the alignment is 0 (i.e., it's defined globally in one file and declared in
another file) it could get an alignment which is larger than the ABI allows for
that type, resulting in aligned moves being used for unaligned loads.

For instance, in file A.c:

   struct S s;

In file B.c:
   struct {
     // something long
   };
   extern S s;

   void foo() {
     struct S p = s;
     // ...
   }

this copy is a 'memcpy' which is turned into a series of 'movaps' instructions
on X86. But this is wrong, because 'struct S' has alignment of 4, not 16.

llvm-svn: 140902

2011-09-30 23:19:55 +00:00

3 Commits