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author | Chris Lattner <sabre@nondot.org> | 2008-01-27 17:42:27 +0000 |
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committer | Chris Lattner <sabre@nondot.org> | 2008-01-27 17:42:27 +0000 |
commit | 3bd39d4ca89804e97c93b039f6c2933f514c165c (patch) | |
tree | cd7a724754e525a6f5dbaebd96905710c907b6fe /test/CodeGen/X86 | |
parent | f6b935d8e696f221eeb0578aa3da7cc143f80049 (diff) | |
download | external_llvm-3bd39d4ca89804e97c93b039f6c2933f514c165c.zip external_llvm-3bd39d4ca89804e97c93b039f6c2933f514c165c.tar.gz external_llvm-3bd39d4ca89804e97c93b039f6c2933f514c165c.tar.bz2 |
Implement some dag combines that allow doing fneg/fabs/fcopysign in integer
registers if used by a bitconvert or using a bitconvert. This allows us to
avoid constant pool loads and use cheaper integer instructions when the
values come from or end up in integer regs anyway. For example, we now
compile CodeGen/X86/fp-in-intregs.ll to:
_test1:
movl $2147483648, %eax
xorl 4(%esp), %eax
ret
_test2:
movl $1065353216, %eax
orl 4(%esp), %eax
andl $3212836864, %eax
ret
Instead of:
_test1:
movss 4(%esp), %xmm0
xorps LCPI2_0, %xmm0
movd %xmm0, %eax
ret
_test2:
movss 4(%esp), %xmm0
andps LCPI3_0, %xmm0
movss LCPI3_1, %xmm1
andps LCPI3_2, %xmm1
orps %xmm0, %xmm1
movd %xmm1, %eax
ret
bitconverts can happen due to various calling conventions that require
fp values to passed in integer regs in some cases, e.g. when returning
a complex.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46414 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/X86')
-rw-r--r-- | test/CodeGen/X86/fp-in-intregs.ll | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/test/CodeGen/X86/fp-in-intregs.ll b/test/CodeGen/X86/fp-in-intregs.ll new file mode 100644 index 0000000..1e3ea89 --- /dev/null +++ b/test/CodeGen/X86/fp-in-intregs.ll @@ -0,0 +1,21 @@ +; RUN: llvm-as < %s | llc -march=x86 -mcpu=yonah | not egrep {\(\(xor\|and\)ps\|movd\)} + +; These operations should be done in integer registers, eliminating constant +; pool loads, movd's etc. + +define i32 @test1(float %x) nounwind { +entry: + %tmp2 = sub float -0.000000e+00, %x ; <float> [#uses=1] + %tmp210 = bitcast float %tmp2 to i32 ; <i32> [#uses=1] + ret i32 %tmp210 +} + +define i32 @test2(float %x) nounwind { +entry: + %tmp2 = tail call float @copysignf( float 1.000000e+00, float %x ) nounwind readnone ; <float> [#uses=1] + %tmp210 = bitcast float %tmp2 to i32 ; <i32> [#uses=1] + ret i32 %tmp210 +} + +declare float @copysignf(float, float) nounwind readnone + |