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 02:16:49 +02:00
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; RUN: llvm-as < %s | llc -march=x86 -mcpu=yonah | not grep {sub.*esp}
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2009-01-19 09:08:22 +01:00
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; RUN: llvm-as < %s | llc -march=x86 -mcpu=yonah | grep cvtsi2ss
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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 02:16:49 +02:00
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; rdar://6034396
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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"
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target triple = "i386-apple-darwin8"
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define void @test(i32 %x, float* %y) nounwind {
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entry:
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lshr i32 %x, 23 ; <i32>:0 [#uses=1]
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uitofp i32 %0 to float ; <float>:1 [#uses=1]
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store float %1, float* %y
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ret void
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}
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