Commit Graph

6 Commits

Author SHA1 Message Date
Chris Lattner
b31189f262 fix PR5978 by peeling the loop so that we avoid shifting the
result int by 8 for the first byte.  While normally harmless,
if the result is smaller than a byte, this shift is invalid.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93018 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-08 19:02:23 +00:00
Chris Lattner
44a7a380aa Fix PR5551 by not ignoring the top level constantexpr when
folding a load from constant.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90545 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-04 06:29:29 +00:00
Chris Lattner
c5af649758 fix PR5287, a serious regression from my previous patches. Thanks to
Duncan for the nice tiny testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84992 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-24 05:22:15 +00:00
Chris Lattner
17f0cd3cc1 teach libanalysis to simplify vector loads with bitcast sources. This
implements something out of Target/README.txt producing:

_foo:                                                       ## @foo
	movl	4(%esp), %eax
	movapd	LCPI1_0, %xmm0
	movapd	%xmm0, (%eax)
	ret	$4

instead of:

_foo:                                                       ## @foo
	movl	4(%esp), %eax
	movapd	_b, %xmm0
	mulpd	LCPI1_0, %xmm0
	addpd	_a, %xmm0
	movapd	%xmm0, (%eax)
	ret	$4



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84942 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-23 06:57:37 +00:00
Chris Lattner
739208a790 enhance FoldReinterpretLoadFromConstPtr to handle loads of up to 32
bytes (i256).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84941 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-23 06:50:36 +00:00
Chris Lattner
fe8c7c807c teach libanalysis to fold int and fp loads from almost arbitrary
non-type-safe constant initializers.  This sort of thing happens
quite a bit for 4-byte loads out of string constants, unions, 
bitfields, and an interesting endianness check from sqlite, which
is something like this:

const int sqlite3one = 1;
# define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
# define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
# define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)

all of these macros now constant fold away.

This implements PR3152 and is based on a patch started by Eli, but heavily
modified and extended.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84936 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-23 06:23:49 +00:00