Commit Graph

7 Commits

Author SHA1 Message Date
Evan Cheng
e721f5c8d3 Improve codegen for select's:
if (x != 0) x = 1
if (x == 1) x = 1

Previous codegen looks like this:
        mov     r1, r0
        cmp     r1, #1
        mov     r0, #0
        moveq   r0, #1

The naive lowering select between two different values. It should recognize the
test is equality test so it's more a conditional move rather than a select:
        cmp     r0, #1
        movne   r0, #0

rdar://9758317


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135017 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-13 00:42:17 +00:00
Jakob Stoklund Olesen
28e104bcb0 Explicitly request physreg coalesing for a bunch of Thumb2 unit tests.
These tests all follow the same pattern:

	mov	r2, r0
	movs	r0, #0
	$CMP	r2, r1
	it	eq
	moveq	r0, #1
	bx	lr

The first 'mov' can be eliminated by rematerializing 'movs r0, #0' below the
test instruction:

	$CMP	r0, r1
	mov.w	r0, #0
	it	eq
	moveq	r0, #1
	bx	lr

So far, only physreg coalescing can do that. The register allocators won't yet
split live ranges just to eliminate copies. They can learn, but this particular
problem is not likely to show up in real code. It only appears because r0 is
used for both the function argument and return value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130858 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-04 19:02:07 +00:00
Edward O'Callaghan
f4a93dd70e Convert Thumb2 tests to FileCheck for PR5307.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89595 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-22 15:18:27 +00:00
Dan Gohman
fce288fc91 Eliminate more uses of llvm-as and llvm-dis.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81293 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-09 00:09:15 +00:00
Chris Lattner
fc227be725 update various tests for signedness changes in .s file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81289 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-08 23:51:06 +00:00
David Goodwin
af0d08d55c Add ".w" suffix for wide thumb-2 instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77199 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-27 16:31:55 +00:00
David Goodwin
baeb911d60 Add Thumb-2 support for TEQ amd TST.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74468 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-29 22:49:42 +00:00