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Implement blm and bls using an inline loop.

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This replaces a call to memmove() in libc.  That was working for me,
but it can fail because EM programs don't always link to libc.

blm and bls only need to copy aligned words.  They don't need to copy
bytes, and they don't need to copy between overlapping buffers, as
memmove() does.  So the new loop is simpler than memmove().
This commit is contained in:
George Koehler 2017-02-11 19:30:12 -05:00
parent c578c495bb
commit 2e41c392fa
1 changed files with 15 additions and 15 deletions
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30
mach/powerpc/ncg/table
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@ -289,6 +289,7 @@ INSTRUCTIONS
andisX "andis." GPR:wo:cc, GPR:ro, CONST:ro.
b LABEL:ro.
bc CONST:ro, CONST:ro, LABEL:ro.
bdnz LABEL:ro.
beq LABEL:ro.
bne LABEL:ro.
bgt LABEL:ro.
@ -362,6 +363,7 @@ INSTRUCTIONS
rlwinm GPR:wo, GPR:ro, CONST:ro, CONST:ro, CONST:ro.
extlwi GPR:wo, GPR:ro, CONST:ro, CONST:ro.
extrwi GPR:wo, GPR:ro, CONST:ro, CONST:ro.
srwi GPR:wo, GPR:ro, CONST:ro.
slw GPR:wo, GPR:ro, GPR:ro.
subf GPR:wo, GPR:ro, GPR:ro.
sraw GPR:wo, GPR:ro, GPR:ro cost(4, 2).
@ -1930,24 +1932,22 @@ PATTERNS
b {LABEL, ".ret"}
pat blm /* Block move constant length */
with REG REG STACK
uses REG
gen
move {CONST, $1}, %a
stwu %a, {IND_RC_W, SP, 0-4}
stwu %2, {IND_RC_W, SP, 0-4}
stwu %1, {IND_RC_W, SP, 0-4}
bl {LABEL, "_memmove"}
addi SP, SP, {CONST, 12}
leaving
loc $1
bls
pat bls /* Block move variable length */
with REG REG REG STACK
with REG REG REG
uses reusing %1, REG, REG={CONST_0000_7FFF, 0}
gen
stwu %1, {IND_RC_W, SP, 0-4}
stwu %3, {IND_RC_W, SP, 0-4}
stwu %2, {IND_RC_W, SP, 0-4}
bl {LABEL, "_memmove"}
addi SP, SP, {CONST, 12}
/* Wrong if size is zero */
srwi %1, %1, {CONST, 2}
mtspr CTR, %1
1:
lwzx %a, %3, %b
stwx %a, %2, %b
addi %b, %b, {CONST, 4}
bdnz {LABEL, "1b"}
pat csa /* Array-lookup switch */
with STACK