llvm-mirror/test/CodeGen/Thumb2/thumb2-cmp2.ll
Jakob Stoklund Olesen 780e6d1f64 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.

llvm-svn: 130858
2011-05-04 19:02:07 +00:00

53 lines
1.1 KiB
LLVM

; RUN: llc < %s -march=thumb -mattr=+thumb2 -join-physregs | FileCheck %s
; These tests implicitly depend on 'movs r0, #0' being rematerialized below the
; test as 'mov.w r0, #0'. So far, that requires physreg joining.
define i1 @f1(i32 %a, i32 %b) {
; CHECK: f1:
; CHECK: cmp r0, r1
%tmp = icmp ne i32 %a, %b
ret i1 %tmp
}
define i1 @f2(i32 %a, i32 %b) {
; CHECK: f2:
; CHECK: cmp r0, r1
%tmp = icmp eq i32 %a, %b
ret i1 %tmp
}
define i1 @f6(i32 %a, i32 %b) {
; CHECK: f6:
; CHECK: cmp.w r0, r1, lsl #5
%tmp = shl i32 %b, 5
%tmp1 = icmp eq i32 %tmp, %a
ret i1 %tmp1
}
define i1 @f7(i32 %a, i32 %b) {
; CHECK: f7:
; CHECK: cmp.w r0, r1, lsr #6
%tmp = lshr i32 %b, 6
%tmp1 = icmp ne i32 %tmp, %a
ret i1 %tmp1
}
define i1 @f8(i32 %a, i32 %b) {
; CHECK: f8:
; CHECK: cmp.w r0, r1, asr #7
%tmp = ashr i32 %b, 7
%tmp1 = icmp eq i32 %a, %tmp
ret i1 %tmp1
}
define i1 @f9(i32 %a, i32 %b) {
; CHECK: f9:
; CHECK: cmp.w r0, r0, ror #8
%l8 = shl i32 %a, 24
%r8 = lshr i32 %a, 8
%tmp = or i32 %l8, %r8
%tmp1 = icmp ne i32 %a, %tmp
ret i1 %tmp1
}