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* optimized PowerPC version of changes in r35454

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git-svn-id: trunk@35458 -
This commit is contained in:
Jonas Maebe 2017-02-19 20:27:39 +00:00
parent 99a0c2464d
commit 1b42affa8f
1 changed files with 3 additions and 34 deletions
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37
rtl/powerpc/int64p.inc
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@ -145,45 +145,16 @@
function fpc_mul_qword(f1,f2 : qword) : qword;[public,alias: 'FPC_MUL_QWORD']; compilerproc;
assembler; nostackframe;
asm
// (r3:r4) = (r3:r4) * (r5:r6), checkoverflow is in r7
// (r3:r4) = (r3:r4) * (r5:r6)
// res f1 f2
or. r10,r3,r5 // are both msw's 0?
mulhwu r8,r4,r6 // msw of product of lsw's
not r0,r7 // if no overflowcheck, r0 := $ffffffff, else r0 := 0;
beq .LDone // if both msw's are zero, skip cross products
mullw r9,r4,r5 // lsw of first cross-product
cntlzw r11,r3 // count leading zeroes of msw1
cntlzw r12,r5 // count leading zeroes of msw2
mullw r7,r3,r6 // lsw of second cross-product
add r12,r11,r12 // sum of leading zeroes
mr r10,r8
or r0,r12,r0 // maximise sum if no overflow checking, otherwise it remains
add r8,r8,r9 // add
cmplwi cr1,r0,64 // >= 64 leading zero bits in total? If so, no overflow
add r8,r8,r7 // add
bge+ cr1,.LDone // if the sum of leading zero's >= 64 (or checkoverflow was 0)
// there's no overflow, otherwise more thorough check
add r7,r7,r9
mulhwu r3,r6,r3
addc r7,r7,r10 // add the msw of the product of the lsw's, record carry
cntlzw r9,r5
cntlzw r10,r4 // get leading zeroes count of lsw f1
mulhwu r5,r4,r5
addze r3,r3
subfic r0,r11,31 // if msw f1 = 0, then r0 := -1, else r0 >= 0
cntlzw r7,r6
subfic r11,r9,31 // same for f2
srawi r0,r0,31 // if msw f1 = 0, then r0 := 1, else r0 := 0
srawi r11,r11,31
and r10,r10,r0 // if msw f1 <> 0, the leading zero count lsw f1 := 0
and r9,r7,r11 // same for f2
or. r5,r5,r3
add r9,r9,r10 // add leading zero counts of lsw's to sum if appropriate
add r9,r9,r12
cmplwi cr7,r9,64 // is the sum now >= 64?
cmplwi cr1,r9,62 // or <= 62?
.LDone:
mullw r4,r4,r6 // lsw of product of lsw's
mr r3,r8 // get msw of product in correct register
@ -193,12 +164,11 @@
function fpc_mul_qword_checkoverflow(f1,f2 : qword) : qword;[public,alias: 'FPC_MUL_QWORD_CHECKOVERFLOW']; compilerproc;
assembler; nostackframe;
asm
// (r3:r4) = (r3:r4) * (r5:r6), checkoverflow is in r7
// (r3:r4) = (r3:r4) * (r5:r6)
// res f1 f2
or. r10,r3,r5 // are both msw's 0?
mulhwu r8,r4,r6 // msw of product of lsw's
xor r0,r0,r0 // r0 := 0 for overflow checking
beq .LDone // if both msw's are zero, skip cross products
mullw r9,r4,r5 // lsw of first cross-product
cntlzw r11,r3 // count leading zeroes of msw1
@ -206,9 +176,8 @@
mullw r7,r3,r6 // lsw of second cross-product
add r12,r11,r12 // sum of leading zeroes
mr r10,r8
or r0,r12,r0 // maximise sum if no overflow checking, otherwise it remains
add r8,r8,r9 // add
cmplwi cr1,r0,64 // >= 64 leading zero bits in total? If so, no overflow
cmplwi cr1,r12,64 // >= 64 leading zero bits in total? If so, no overflow
add r8,r8,r7 // add
bge+ cr1,.LDone // if the sum of leading zero's >= 64 (or checkoverflow was 0)
// there's no overflow, otherwise more thorough check