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Experiment with conversions between integers and floats.

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Switch some conversions from libem calls to inline code.  The
conversions from integers to floats are now too slow, because each
conversion allocates 4 or 5 registers, and the register allocator is
too slow.  I might use these slow conversions to experiment with the
register allocator.

I add the missing conversions between 4-byte single floats and
integers, simply by going through 8-byte double floats.  (These
replace the calls to nonexistant functions in libem.)

I remove the placeholder for fef 4, because it doesn't exist in libem,
and our language runtimes only use fef 8.
This commit is contained in:
George Koehler 2017-02-11 23:23:47 -05:00
parent 2e41c392fa
commit 1de1e8f7f0
1 changed files with 87 additions and 34 deletions
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121
mach/powerpc/ncg/table
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@ -320,6 +320,7 @@ INSTRUCTIONS
fadds FSREG:wo, FSREG:ro, FSREG:ro cost(4, 5).
fcmpo CR:wo, FREG:ro, FREG:ro cost(4, 5).
fcmpo CR:wo, FSREG:ro, FSREG:ro cost(4, 5).
fctiwz FREG:wo, FREG:ro.
fdiv FREG:wo, FREG:ro, FREG:ro cost(4, 35).
fdivs FSREG:wo, FSREG:ro, FSREG:ro cost(4, 21).
fmr FPR:wo, FPR:ro cost(4, 5).
@ -2198,30 +2199,45 @@ PATTERNS
with FSREG
yields %1.1
pat loc loc cfu $1==INT32 && $2==INT32 /* Convert single to unsigned int */
with STACK
gen
bl {LABEL, ".cfu4"}
/* Convert single to signed int */
pat loc loc cfi $1==4 && $2==4
leaving
loc 4
loc 8
cff
loc 8
loc 4
cfi
pat loc loc cfi $1==INT32 && $2==INT32 /* Convert single to signed int */
with STACK
gen
bl {LABEL, ".cfi4"}
/* Convert single to unsigned int */
pat loc loc cfu $1==4 && $2==4
leaving
loc 4
loc 8
cff
loc 8
loc 4
cfu
pat loc loc cif $1==INT32 && $2==INT32 /* Convert integer to single */
with STACK
gen
bl {LABEL, ".cif4"}
/* Convert signed int to single */
pat loc loc cif $1==4 && $2==4
leaving
loc 4
loc 8
cif
loc 8
loc 4
cff
pat loc loc cuf $1==INT32 && $2==INT32 /* Convert unsigned int to single */
with STACK
gen
bl {LABEL, ".cuf4"}
pat fef $1==INT32 /* Split single */
with STACK
gen
bl {LABEL, ".fef4"}
/* Convert unsigned int to single */
pat loc loc cuf $1==4 && $2==4
leaving
loc 4
loc 8
cuf
loc 8
loc 4
cff
/* Double-precision */
@ -2328,26 +2344,63 @@ PATTERNS
frsp %a, %1
yields %a
pat loc loc cfu $1==INT64 && $2==INT32 /* Convert double to unsigned int */
/* Convert double to signed int */
pat loc loc cfi $1==8 && $2==4
with FREG STACK
uses reusing %1, FREG
gen
fctiwz %a, %1
stfdu %a, {IND_RC_D, SP, 0-8}
addi SP, SP, {CONST, 4}
/* Convert double to unsigned int */
pat loc loc cfu $1==8 && $2==4
with STACK
gen
bl {LABEL, ".cfu8"}
pat loc loc cfi $1==INT64 && $2==INT32 /* Convert double to signed int */
with STACK
/*
* To convert integer to IEEE double, we pack the integer in
* the low bits of the magic double
* 1 << 52 == 0x 4330 0000 0000 0000
*
* For signed integer i, we flip its sign bit, then compute
* ((1 << 52) + i) - ((1 << 52) + (1 << 31))
*/
pat loc loc cif $1==4 && $2==8
with REG
uses reusing %1, REG={XOR_RIS, %1, 0x8000},
REG={CONST_HZ, 0x43300000},
REG={CONST_HZ, 0x80000000},
FREG, FREG
gen
bl {LABEL, ".cfi8"}
stwu %b, {IND_RC_W, SP, 0-8}
stw %a, {IND_RC_W, SP, 4}
lfd %d, {IND_RC_D, SP, 0}
stw %c, {IND_RC_W, SP, 4}
lfd %e, {IND_RC_D, SP, 0}
fsub %d, %d, %e
addi SP, SP, {CONST, 8}
yields %d
pat loc loc cif $1==INT32 && $2==INT64 /* Convert integer to double */
with STACK
kills ALL
/*
* To convert unsigned integer u to IEEE double, we compute
* ((1 << 52) + u) - (1 << 52)
*/
pat loc loc cuf $1==4 && $2==8
with REG
uses REG={CONST_HZ, 0x43300000},
REG={CONST_0000_7FFF, 0},
FREG, FREG
gen
bl {LABEL, ".cif8"}
pat loc loc cuf $1==INT32 && $2==INT64 /* Convert unsigned int to double */
with STACK
gen
bl {LABEL, ".cuf8"}
stwu %a, {IND_RC_W, SP, 0-8}
stw %1, {IND_RC_W, SP, 4}
lfd %c, {IND_RC_D, SP, 0}
stw %b, {IND_RC_W, SP, 4}
lfd %d, {IND_RC_D, SP, 0}
fsub %c, %c, %d
addi SP, SP, {CONST, 8}
yields %c
pat fef $1==INT64 /* Split exponent, fraction */
with GPR3 GPR4