llvm-mirror/test/CodeGen/X86/uint_to_fp.ll
Chris Lattner 2b67ff8632 when we know the signbit of an input to uint_to_fp is zero,
change it to sint_to_fp on targets where that is cheaper (and
visaversa of course).  This allows us to compile uint_to_fp to:

_test:
	movl	4(%esp), %eax
	shrl	$23, %eax
	cvtsi2ss	%eax, %xmm0
	movl	8(%esp), %eax
	movss	%xmm0, (%eax)
	ret

instead of:

	.align	3
LCPI1_0:					##  double
	.long	0	## double least significant word 4.5036e+15
	.long	1127219200	## double most significant word 4.5036e+15
	.text
	.align	4,0x90
	.globl	_test
_test:
	subl	$12, %esp
	movl	16(%esp), %eax
	shrl	$23, %eax
	movl	%eax, (%esp)
	movl	$1127219200, 4(%esp)
	movsd	(%esp), %xmm0
	subsd	LCPI1_0, %xmm0
	cvtsd2ss	%xmm0, %xmm0
	movl	20(%esp), %eax
	movss	%xmm0, (%eax)
	addl	$12, %esp
	ret

llvm-svn: 52747
2008-06-26 00:16:49 +00:00

14 lines
449 B
LLVM

; RUN: llvm-as < %s | llc -march=x86 -mcpu=yonah | not grep {sub.*esp}
; rdar://6034396
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i386-apple-darwin8"
define void @test(i32 %x, float* %y) nounwind {
entry:
lshr i32 %x, 23 ; <i32>:0 [#uses=1]
uitofp i32 %0 to float ; <float>:1 [#uses=1]
store float %1, float* %y
ret void
}