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new-ra weirdness
- From: <tm_gccmail at mail dot kloo dot net>
- To: matz at suse dot de
- Cc: gcc-bugs at gcc dot gnu dot org, aoliva at redhat dot com,joern dot rennecke at superh dot com, tm at kloo dot net
- Date: Tue, 15 Jul 2003 16:06:49 -0700 (PDT)
- Subject: new-ra weirdness
host: i386-linux
target: sh-elf
version: CVS head today
new-ra is performing unspeakable acts on some of my SH4 testcases.
It seems to be spilling the FPU registers to integer registers....through
memory. There is no fast way to move the FPU registers to the integer
registers on the SH4, so it shouldn't be doing this at all.
Also, it seems to be generating lots of useless loads and stores.
It loads a DFmode value into two integer pairs, then does nothing
and stores it back.
Here's some samples from quatern.i from stress-1.17 compiled with
-O2 -m4 -fnew-ra:
_Normal_Calc_z3:
...
mov.l r3,@-r15
mov.l r2,@-r15
...
fmov.s @r15+,fr2
fmov.s @r15+,fr3
...
mov.l r3,@-r15
mov.l r2,@-r15
...
fmov.s @r15+,fr6
fmov.s @r15+,fr7
...
mov.l r3,@-r15
mov.l r2,@-r15
fmov.s @r15+,fr14
fmov.s @r15+,fr15
...
fmov.s fr7,@-r15
fmov.s fr6,@-r15
mov.l @r15+,r10
mov.l @r15+,r11
...
fmov.s fr7,@-r15
fmov.s fr6,@-r15
mov.l @r15+,r2
mov.l @r15+,r3
...
fmov.s fr3,@-r15 <- do 16 memory load/stores to execute one
fmov.s fr2,@-r15 <- floating-point multiply
mov.l @r15+,r10
mov.l @r15+,r11
mov.l r11,@-r15
mov.l r10,@-r15
fmov.s @r15+,fr14
fmov.s @r15+,fr15
mov.l r3,@-r15
mov.l r2,@-r15
fmov.s @r15+,fr2
fmov.s @r15+,fr3
fmul dr2,dr14
fmov.s fr15,@-r15
fmov.s fr14,@-r15
mov.l @r15+,r10
mov.l @r15+,r11
,,,
mov.l @r15+,r2 <- load r2/r3...
mov.l @r15+,r3
fmov.s @r0,fr3
mov #8,r0
mov.l r3,@-r15 <- save back r2/r3 unchanged!!!
mov.l r2,@-r15
...
mov.l @r15+,r2 <- load r2/r3...
mov.l @r15+,r3
fmov.s @r0,fr7
mov #24,r0
mov.l r3,@-r15 <- save back r2/r3 unchanged!!!
mov.l r2,@-r15
...
mov.l @r15+,r2 <- load r2/r3...
mov.l @r15+,r3
mov.l r3,@-r15 <- save back r2/r3 unchanged!!!
mov.l r2,@-r15
...
mov.l @r15+,r10
mov.l @r15+,r11
mov.l r11,@-r15
mov.l r10,@-r15
...
mov.l @r15+,r2 <- load r2/r3
mov.l @r15+,r3
fmov.s @r0,fr3
mov #48,r0
mov.l r3,@-r15 <- save back r2/r3 unchanged!!!
mov.l r2,@-r15
...
mov.l @r15+,r2
mov.l @r15+,r3
fmov.s @r0,fr3
mov #48,r0
mov.l r3,@-r15
mov.l r2,@-r15
...
mov.l @r15+,r2
mov.l @r15+,r3
fmov.s @r0,fr7
mov #72,r0
mov.l r3,@-r15
mov.l r2,@-r15
...
Have any idea what's going on?
Toshi