Commit Graph

14 Commits

Author SHA1 Message Date
Dan Gohman
0dd3549edc Constant fold x == undef to undef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107074 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-28 21:30:07 +00:00
Chris Lattner
c8e14b3d37 fix incorrect folding of icmp with undef, PR6481.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97659 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-03 19:46:03 +00:00
Chris Lattner
6304b0dd63 fix PR6195, a bug constant folding scalar -> vector compares.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94997 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-01 20:04:40 +00:00
Chris Lattner
3bf6815556 enhance x-(-A) -> x+A to preserve NUW/NSW.
Use the presence of NSW/NUW to fold "icmp (x+cst), x" to a constant in
cases where it would otherwise be undefined behavior.

Surprisingly (to me at least), this triggers hundreds of the times in
a few benchmarks: lencode, ldecode, and 466.h264ref seem to *really*
like this.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91812 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-21 04:04:05 +00:00
Chris Lattner
2799bafb98 Optimize all cases of "icmp (X+Cst), X" to something simpler. This triggers
a bunch in lencode, ldecod, spass, 176.gcc, 252.eon, among others.  It is 
also the first part of PR5822


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91811 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-21 03:19:28 +00:00
Chris Lattner
6b57a797ab convert to filecheck
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91810 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-21 03:11:05 +00:00
Chris Lattner
0036e3a469 simplify a transformation by making it more general.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83792 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-11 21:22:21 +00:00
Dan Gohman
3e054fe9ef Use opt -S instead of piping bitcode output through llvm-dis.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81257 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-08 22:34:10 +00:00
Dan Gohman
b1e1e82c54 Change these tests to feed the assembly files to opt directly, instead
of using llvm-as, now that opt supports this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81226 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-08 16:50:01 +00:00
Chris Lattner
9e17b632ec fix PR4837, some bugs folding vector compares. These
return a vector of i1, not i1 itself.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80761 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-02 05:12:37 +00:00
Chris Lattner
a80d668215 Implement rdar://6480391, extending of equality icmp's to avoid a truncation.
I noticed this in the code compiled for a routine using std::map, which produced
this code:
	%25 = tail call i32 @memcmp(i8* %24, i8* %23, i32 6) nounwind readonly
	%.lobit.i = lshr i32 %25, 31		; <i32> [#uses=1]
	%tmp.i = trunc i32 %.lobit.i to i8		; <i8> [#uses=1]
	%toBool = icmp eq i8 %tmp.i, 0		; <i1> [#uses=1]
	br i1 %toBool, label %bb3, label %bb4
which compiled to:

	call	L_memcmp$stub
	shrl	$31, %eax
	testb	%al, %al
	jne	LBB1_11	## 

with this change, we compile it to:

	call	L_memcmp$stub
	testl	%eax, %eax
	js	LBB1_11

This triggers all the time in common code, with patters like this:

	%169 = and i32 %ply, 1		; <i32> [#uses=1]
	%170 = trunc i32 %169 to i8		; <i8> [#uses=1]
	%toBool = icmp ne i8 %170, 0		; <i1> [#uses=1]

 	%7 = lshr i32 %6, 24		; <i32> [#uses=1]
	%9 = trunc i32 %7 to i8		; <i8> [#uses=1]
	%10 = icmp ne i8 %9, 0		; <i1> [#uses=1]

etc



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61985 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-09 07:47:06 +00:00
Reid Spencer
2b544beda3 For PR1319:
Upgrade tests to work with new llvm.exp version of llvm_runtest.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36013 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-14 20:13:02 +00:00
Chris Lattner
12f591342f sext of compares.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35892 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-11 06:57:54 +00:00
Chris Lattner
f6e166b386 new testcase
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35889 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-11 06:52:24 +00:00