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ack/mach/powerpc/libem/xor.s

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Add Modula-2 set operations to PowerPC ncg. This provides and, ior, xor, com, zer, set, cms when defined($1) and ior, set when !defined($1). I don't provide the other operations !defined($1) because our Modula-2 compiler hasn't used them. I wrote a Modula-2 example in https://gist.github.com/kernigh/add79662bb3c63ffb7c46d01dc8ae788 Put a dummy comment in mach/powerpc/libem/build.lua so git checkout will touch that file. Without the touch, the build system doesn't see the new *.s files.
2016-12-10 17:23:07 +00:00
.sect .text
! Set symmetric difference.
Use lwzu, stwu to tighten more loops. Because lwzu or stwu moves the pointer, I can remove an addi instruction from the loop, so the loop is slightly faster. I wrote a benchmark in Modula-2 that exercises some of these loops. I measured its time on my old PowerPC Mac. Its user time decreases from 8.401s to 8.217s with the tighter loops.
2017-10-18 16:12:42 +00:00
! Stack: ( a b size -- a/b )
Add Modula-2 set operations to PowerPC ncg. This provides and, ior, xor, com, zer, set, cms when defined($1) and ior, set when !defined($1). I don't provide the other operations !defined($1) because our Modula-2 compiler hasn't used them. I wrote a Modula-2 example in https://gist.github.com/kernigh/add79662bb3c63ffb7c46d01dc8ae788 Put a dummy comment in mach/powerpc/libem/build.lua so git checkout will touch that file. Without the touch, the build system doesn't see the new *.s files.
2016-12-10 17:23:07 +00:00
.define .xor
.xor:
Edit PowerPC assembly for .and, .cms, .ior, .xor, .zer Remove one addi instruction from some loops. These loops had increased 2 pointers, they now increase 1 index. I must initialize the index, so I add "li r6, 0" before each loop. Change .zer to use subf instead of neg, add. Change .xor to take the size on the real stack, as .and and .or have done since 81c677d.
2017-02-11 23:00:56 +00:00
lwz r3, 0(sp) ! r3 = size
srwi r7, r3, 2
mtspr ctr, r7 ! ctr = size / 4
Use lwzu, stwu to tighten more loops. Because lwzu or stwu moves the pointer, I can remove an addi instruction from the loop, so the loop is slightly faster. I wrote a benchmark in Modula-2 that exercises some of these loops. I measured its time on my old PowerPC Mac. Its user time decreases from 8.401s to 8.217s with the tighter loops.
2017-10-18 16:12:42 +00:00
add r4, sp, r3 ! r4 = pointer before set a
! Loop with r4 in set a and sp in set b.
1: lwzu r5, 4(r4)
lwzu r6, 4(sp)
xor r7, r5, r6 ! symmetric difference of words
stw r7, 0(r4)
In PowerPC libem, use the new features of our assembler. The new features are the hi16/lo16 and ha16/lo16 syntax for relocations, and the extended mnemonics like "blr". Use ha16/lo16 to load some double floats with 2 instructions (lis/lfd) instead of 3 (lis/ori/lfd). Use the extended names for branches, comparisons, and bit rotations, so I can more easily read the code. The new names often encode the same machine instructions as the old names, except in a few places where I changed the instructions. Stop using andi. when we don't need to set cr0. In inn.s, I change andi. to extrwi to extract the same bits. In los.s and sts.s, I change "andi. r3, r3, ~3" to "clrrwi r3, r3, 2". This avoids setting cr0 and also stops clearing the high 16 bits of r3. In csa.s, los.s, sts.s, I change some comparisons and right shifts from signed to unsigned (cmplw, cmplwi, srwi), because the sizes are unsigned. In inn.s, the right shift can be signed (sraw) or unsigned (srw), but I use srw because we don't need the carry bit. In fef8.s, I save an instruction by using rlwinm instead of addis/andc to rlwinm to clear a field. The code no longer kills r7. In both fef8.s and fif8.s, I remove the list of killed registers. Also remove some whitespace from ends of lines.
2017-01-23 22:16:39 +00:00
bdnz 1b ! loop ctr times
Use lwzu, stwu to tighten more loops. Because lwzu or stwu moves the pointer, I can remove an addi instruction from the loop, so the loop is slightly faster. I wrote a benchmark in Modula-2 that exercises some of these loops. I measured its time on my old PowerPC Mac. Its user time decreases from 8.401s to 8.217s with the tighter loops.
2017-10-18 16:12:42 +00:00
addi sp, sp, 4 ! drop last word of set b
In PowerPC libem, use the new features of our assembler. The new features are the hi16/lo16 and ha16/lo16 syntax for relocations, and the extended mnemonics like "blr". Use ha16/lo16 to load some double floats with 2 instructions (lis/lfd) instead of 3 (lis/ori/lfd). Use the extended names for branches, comparisons, and bit rotations, so I can more easily read the code. The new names often encode the same machine instructions as the old names, except in a few places where I changed the instructions. Stop using andi. when we don't need to set cr0. In inn.s, I change andi. to extrwi to extract the same bits. In los.s and sts.s, I change "andi. r3, r3, ~3" to "clrrwi r3, r3, 2". This avoids setting cr0 and also stops clearing the high 16 bits of r3. In csa.s, los.s, sts.s, I change some comparisons and right shifts from signed to unsigned (cmplw, cmplwi, srwi), because the sizes are unsigned. In inn.s, the right shift can be signed (sraw) or unsigned (srw), but I use srw because we don't need the carry bit. In fef8.s, I save an instruction by using rlwinm instead of addis/andc to rlwinm to clear a field. The code no longer kills r7. In both fef8.s and fif8.s, I remove the list of killed registers. Also remove some whitespace from ends of lines.
2017-01-23 22:16:39 +00:00
blr
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