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llvm-svn: 48912
This commit is contained in:
Evan Cheng 2008-03-28 07:07:06 +00:00
parent 9ae4d7b719
commit 81e0c9a32c
1 changed files with 44 additions and 0 deletions
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44
llvm/lib/Target/X86/README.txt
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@ -1612,3 +1612,47 @@ The coalescer could coalesce "edx" with "eax" to avoid the movl in LBB1_2
if it commuted the addl in LBB1_1.
//===---------------------------------------------------------------------===//
See rdar://4653682.
From flops:
LBB1_15: # bb310
cvtss2sd LCPI1_0, %xmm1
addsd %xmm1, %xmm0
movsd 176(%esp), %xmm2
mulsd %xmm0, %xmm2
movapd %xmm2, %xmm3
mulsd %xmm3, %xmm3
movapd %xmm3, %xmm4
mulsd LCPI1_23, %xmm4
addsd LCPI1_24, %xmm4
mulsd %xmm3, %xmm4
addsd LCPI1_25, %xmm4
mulsd %xmm3, %xmm4
addsd LCPI1_26, %xmm4
mulsd %xmm3, %xmm4
addsd LCPI1_27, %xmm4
mulsd %xmm3, %xmm4
addsd LCPI1_28, %xmm4
mulsd %xmm3, %xmm4
addsd %xmm1, %xmm4
mulsd %xmm2, %xmm4
movsd 152(%esp), %xmm1
addsd %xmm4, %xmm1
movsd %xmm1, 152(%esp)
incl %eax
cmpl %eax, %esi
jge LBB1_15 # bb310
LBB1_16: # bb358.loopexit
movsd 152(%esp), %xmm0
addsd %xmm0, %xmm0
addsd LCPI1_22, %xmm0
movsd %xmm0, 152(%esp)
Rather than spilling the result of the last addsd in the loop, we should have
insert a copy to split the interval (one for the duration of the loop, one
extending to the fall through). The register pressure in the loop isn't high
enough to warrant the spill.
Also check why xmm7 is not used at all in the function.