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PPC: Fuse BAND with shift to rlwinm.

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Mike Pall 2011-10-25 21:29:58 +02:00
parent 455917fa0a
commit 1d190c99a2
1 changed files with 42 additions and 8 deletions
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50
src/lj_asm_ppc.h
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@ -1478,9 +1478,40 @@ static void asm_bitop(ASMState *as, IRIns *ir, PPCIns pi, PPCIns pik)
emit_asb(as, pi, dest, left, right);
}
/* Fuse BAND with contiguous bitmask and a shift to rlwinm. */
static void asm_fuseandsh(ASMState *as, PPCIns pi, int32_t mask, IRRef ref)
{
IRIns *ir;
Reg left;
if (mayfuse(as, ref) && (ir = IR(ref), ra_noreg(ir->r)) &&
irref_isk(ir->op2)) {
int32_t sh = (IR(ir->op2)->i & 31);
switch (ir->o) {
case IR_BSHL:
if ((mask & ((1u<<sh)-1))) goto nofuse;
break;
case IR_BSHR:
if ((mask & ~((~0u)>>sh))) goto nofuse;
sh = ((32-sh)&31);
break;
case IR_BROL:
break;
default:
goto nofuse;
}
left = ra_alloc1(as, ir->op1, RSET_GPR);
*--as->mcp = pi | PPCF_T(left) | PPCF_B(sh);
return;
}
nofuse:
left = ra_alloc1(as, ref, RSET_GPR);
*--as->mcp = pi | PPCF_T(left);
}
static void asm_bitand(ASMState *as, IRIns *ir)
{
Reg dest, left, right;
IRRef lref = ir->op1;
PPCIns dot = 0;
IRRef op2;
if (as->flagmcp == as->mcp) {
@ -1489,48 +1520,51 @@ static void asm_bitand(ASMState *as, IRIns *ir)
dot = PPCF_DOT;
}
dest = ra_dest(as, ir, RSET_GPR);
left = ra_hintalloc(as, ir->op1, dest, RSET_GPR);
if (irref_isk(ir->op2)) {
int32_t k = IR(ir->op2)->i;
if (k) {
// NYI: fuse with shifts/rotates.
/* First check for a contiguous bitmask as used by rlwinm. */
uint32_t s1 = lj_ffs((uint32_t)k);
uint32_t k1 = ((uint32_t)k >> s1);
if ((k1 & (k1+1)) == 0) {
emit_rot(as, PPCI_RLWINM|dot, dest, left, 0,
31-lj_fls((uint32_t)k), 31-s1);
asm_fuseandsh(as, PPCI_RLWINM|dot | PPCF_A(dest) |
PPCF_MB(31-lj_fls((uint32_t)k)) | PPCF_ME(31-s1),
k, lref);
return;
}
if (~(uint32_t)k) {
uint32_t s2 = lj_ffs(~(uint32_t)k);
uint32_t k2 = (~(uint32_t)k >> s2);
if ((k2 & (k2+1)) == 0) {
emit_rot(as, PPCI_RLWINM|dot, dest, left, 0,
32-s2, 30-lj_fls(~(uint32_t)k));
asm_fuseandsh(as, PPCI_RLWINM|dot | PPCF_A(dest) |
PPCF_MB(32-s2) | PPCF_ME(30-lj_fls(~(uint32_t)k)),
k, lref);
return;
}
}
}
if (checku16(k)) {
left = ra_alloc1(as, lref, RSET_GPR);
emit_asi(as, PPCI_ANDIDOT, dest, left, k);
return;
} else if ((k & 0xffff) == 0) {
left = ra_alloc1(as, lref, RSET_GPR);
emit_asi(as, PPCI_ANDISDOT, dest, left, (k >> 16));
return;
}
}
op2 = ir->op2;
if (mayfuse(as, op2) && IR(op2)->o == IR_BNOT) {
if (mayfuse(as, op2) && IR(op2)->o == IR_BNOT && ra_noreg(IR(op2)->r)) {
dot ^= (PPCI_AND ^ PPCI_ANDC);
op2 = IR(op2)->op1;
}
left = ra_hintalloc(as, lref, dest, RSET_GPR);
right = ra_alloc1(as, op2, rset_exclude(RSET_GPR, left));
emit_asb(as, PPCI_AND ^ dot, dest, left, right);
}
static void asm_bitshift(ASMState *as, IRIns *ir, PPCIns pi, PPCIns pik)
{
// NYI: fuse with IR_BAND.
Reg dest, left;
Reg dot = 0;
if (as->flagmcp == as->mcp) {