Commit Graph

16 Commits

Author SHA1 Message Date
Chris Lattner 18d7fc8fc6 Implement a pretty general logical shift propagation
framework, which is good at ripping through bitfield
operations.  This generalize a bunch of the existing
xforms that instcombine does, such as 
  (x << c) >> c -> and
to handle intermediate logical nodes.  This is useful for
ripping up the "promote to large integer" code produced by
SRoA.

llvm-svn: 112304
2010-08-27 22:24:38 +00:00
Chris Lattner 25a198e72b remove some special shift cases that have been subsumed into the
more general simplify demanded bits logic.

llvm-svn: 112291
2010-08-27 21:04:34 +00:00
Gabor Greif 4a39b84a9d use ArgOperand API
llvm-svn: 106707
2010-06-24 00:44:01 +00:00
Eric Christopher 7258dcd77f Revert 101465, it broke internal OpenGL testing.
Probably the best way to know that all getOperand() calls have been handled
is to replace that API instead of updating.

llvm-svn: 101579
2010-04-16 23:37:20 +00:00
Gabor Greif f375520f7b reapply r101434
with a fix for self-hosting

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary

llvm-svn: 101465
2010-04-16 15:33:14 +00:00
Gabor Greif 403e9694f9 back out r101423 and r101397, they break llvm-gcc self-host on darwin10
llvm-svn: 101434
2010-04-16 01:16:20 +00:00
Gabor Greif 33ae80bff7 reapply r101364, which has been backed out in r101368
with a fix

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary

llvm-svn: 101397
2010-04-15 20:51:13 +00:00
Gabor Greif 9fd00c7d25 back out r101364, as it trips the linux nightlybot on some clang C++ tests
llvm-svn: 101368
2010-04-15 12:46:56 +00:00
Gabor Greif aafd209632 rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary

llvm-svn: 101364
2010-04-15 10:49:53 +00:00
Chris Lattner e112ff64c5 fix a potential overflow issue Eli pointed out.
llvm-svn: 94336
2010-01-23 23:31:46 +00:00
Chris Lattner 249da5cb73 implement a simple instcombine xform that has been in the
readme forever.

llvm-svn: 94318
2010-01-23 18:49:30 +00:00
Chris Lattner 43f2fa6201 my instcombine transformations to make extension elimination more
aggressive changed the canonical form from sext(trunc(x)) to ashr(lshr(x)),
make sure to transform a couple more things into that canonical form,
and catch a case where we missed turning zext/shl/ashr into a single sext.

llvm-svn: 93787
2010-01-18 22:19:16 +00:00
Chris Lattner d8509424a4 change the preferred canonical form for a sign extension to be
lshr+ashr instead of trunc+sext.  We want to avoid type 
conversions whenever possible, it is easier to codegen expressions
without truncates and extensions.

llvm-svn: 93107
2010-01-10 07:08:30 +00:00
Chris Lattner 2b459fe7e1 fix indentation of switch statements, no functionality change.
llvm-svn: 93106
2010-01-10 06:59:55 +00:00
Chris Lattner a1e223ea10 teach instcombine to delete sign extending shift pairs (sra(shl X, C), C) when
the input is already sign extended.

llvm-svn: 93019
2010-01-08 19:04:21 +00:00
Chris Lattner dc67e13442 split instcombine of shifts out to its own file.
llvm-svn: 92709
2010-01-05 07:44:46 +00:00