Commit Graph

15 Commits

Author SHA1 Message Date
Eli Friedman 02e737b08e Move "atomic" and "volatile" designations on instructions after the opcode
of the instruction.

Note that this change affects the existing non-atomic load and store
instructions; the parser now accepts both forms, and the change is noted
in the release notes.

llvm-svn: 137527
2011-08-12 22:50:01 +00:00
Chris Lattner 5756c16cdf make the asmparser reject function and type redefinitions. 'Merging' hasn't been
needed since llvm-gcc 3.4 days.

llvm-svn: 133248
2011-06-17 07:06:44 +00:00
Benjamin Kramer fda5dc4968 Revert "InstCombine: Turn mul.with.overflow(X, 2) into the cheaper add.with.overflow(X, X)"
It's better to do this in codegen, mul.with.overflow(X, 2) is more canonical because it has only one use on "X".

llvm-svn: 131798
2011-05-21 18:31:42 +00:00
Benjamin Kramer 691731eb9c InstCombine: Turn mul.with.overflow(X, 2) into the cheaper add.with.overflow(X, X)
llvm-svn: 131789
2011-05-21 09:22:06 +00:00
Eli Friedman 49346010f8 More instcombine cleanup aimed towards improving debug line info.
llvm-svn: 131559
2011-05-18 19:57:14 +00:00
Benjamin Kramer b49b964b98 InstCombine: Turn umul_with_overflow into mul nuw if we can prove that it cannot overflow.
This happens a lot in clang-compiled C++ code because it adds overflow checks to operator new[]:
  unsigned *foo(unsigned n) { return new unsigned[n]; }
We can optimize away the overflow check on 64 bit targets because (uint64_t)n*4 cannot overflow.

llvm-svn: 127418
2011-03-10 18:40:14 +00:00
Chris Lattner 1e8c032a6e X86 supports i8/i16 overflow ops (except i8 multiplies), we should
generate them.  

Now we compile:

define zeroext i8 @X(i8 signext %a, i8 signext %b) nounwind ssp {
entry:
  %0 = tail call %0 @llvm.sadd.with.overflow.i8(i8 %a, i8 %b)
  %cmp = extractvalue %0 %0, 1
  br i1 %cmp, label %if.then, label %if.end

into:

_X:                                     ## @X
## BB#0:                                ## %entry
	subl	$12, %esp
	movb	16(%esp), %al
	addb	20(%esp), %al
	jo	LBB0_2

Before we were generating:

_X:                                     ## @X
## BB#0:                                ## %entry
	pushl	%ebp
	movl	%esp, %ebp
	subl	$8, %esp
	movb	12(%ebp), %al
	testb	%al, %al
	setge	%cl
	movb	8(%ebp), %dl
	testb	%dl, %dl
	setge	%ah
	cmpb	%cl, %ah
	sete	%cl
	addb	%al, %dl
	testb	%dl, %dl
	setge	%al
	cmpb	%al, %ah
	setne	%al
	andb	%cl, %al
	testb	%al, %al
	jne	LBB0_2

llvm-svn: 122186
2010-12-19 20:03:11 +00:00
Chris Lattner 33dc3f0cfa optimize uadd(x, cst) into a comparison when the normal
result is dead.  This is required for my next patch to not
regress the testsuite.

llvm-svn: 122181
2010-12-19 19:35:32 +00:00
Eli Friedman f99e7e6643 PR7853: fix a silly mistake introduced in r101899, and add a test to make sure
it doesn't regress again.

llvm-svn: 110597
2010-08-09 20:49:43 +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 54f4e39956 optimize comparisons against cttz/ctlz/ctpop, patch by Alastair Lynn!
llvm-svn: 92745
2010-01-05 18:09:56 +00:00
Chris Lattner 9da1cb243b optimize cttz and ctlz when we can prove something about the
leading/trailing bits.  Patch by Alastair Lynn!

llvm-svn: 92706
2010-01-05 07:23:56 +00:00
Chris Lattner 8330daf733 add a few trivial instcombines for llvm.powi.
llvm-svn: 92383
2010-01-01 01:52:15 +00:00
Chris Lattner 1cc4cca193 add testcases for the foo_with_overflow op xforms added recently and
fix bugs exposed by the tests.  Testcases from Alastair Lynn!

llvm-svn: 90056
2009-11-29 02:57:29 +00:00
Chris Lattner 39c07b2eef if a 'with overflow' intrinsic just has the normal result used, simplify
it to a normal binop.  Patch by Alastair Lynn, testcase by me.

llvm-svn: 86524
2009-11-09 07:07:56 +00:00