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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. andisX "andis." GPR:wo:cc, GPR:ro, CONST:ro.
b LABEL:ro. b LABEL:ro.
bc CONST:ro, CONST:ro, LABEL:ro. bc CONST:ro, CONST:ro, LABEL:ro.
bdnz LABEL:ro.
beq LABEL:ro. beq LABEL:ro.
bne LABEL:ro. bne LABEL:ro.
bgt LABEL:ro. bgt LABEL:ro.
@ -362,6 +363,7 @@ INSTRUCTIONS
rlwinm GPR:wo, GPR:ro, CONST:ro, CONST:ro, CONST:ro. rlwinm GPR:wo, GPR:ro, CONST:ro, CONST:ro, CONST:ro.
extlwi GPR:wo, GPR:ro, CONST:ro, CONST:ro. extlwi GPR:wo, GPR:ro, CONST:ro, CONST:ro.
extrwi 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. slw GPR:wo, GPR:ro, GPR:ro.
subf GPR:wo, GPR:ro, GPR:ro. subf GPR:wo, GPR:ro, GPR:ro.
sraw GPR:wo, GPR:ro, GPR:ro cost(4, 2). sraw GPR:wo, GPR:ro, GPR:ro cost(4, 2).
@ -1930,24 +1932,22 @@ PATTERNS
b {LABEL, ".ret"} b {LABEL, ".ret"}
pat blm /* Block move constant length */ pat blm /* Block move constant length */
with REG REG STACK leaving
uses REG loc $1
gen bls
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}
pat bls /* Block move variable length */ 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 gen
stwu %1, {IND_RC_W, SP, 0-4} /* Wrong if size is zero */
stwu %3, {IND_RC_W, SP, 0-4} srwi %1, %1, {CONST, 2}
stwu %2, {IND_RC_W, SP, 0-4} mtspr CTR, %1
bl {LABEL, "_memmove"} 1:
addi SP, SP, {CONST, 12} lwzx %a, %3, %b
stwx %a, %2, %b
addi %b, %b, {CONST, 4}
bdnz {LABEL, "1b"}
pat csa /* Array-lookup switch */ pat csa /* Array-lookup switch */
with STACK with STACK