ARM64: Fuse FP multiply-add/sub.

Contributed by Djordje Kovacevic and Stefan Pejic from RT-RK.com.
This commit is contained in:
Mike Pall 2016-12-08 01:38:09 +01:00
parent bfeb1167cd
commit 2772cbc36e
2 changed files with 30 additions and 2 deletions

View File

@ -327,6 +327,27 @@ static void asm_fusexref(ASMState *as, A64Ins ai, Reg rd, IRRef ref,
emit_lso(as, ai, (rd & 31), base, ofs); emit_lso(as, ai, (rd & 31), base, ofs);
} }
/* Fuse FP multiply-add/sub. */
static int asm_fusemadd(ASMState *as, IRIns *ir, A64Ins ai, A64Ins air)
{
IRRef lref = ir->op1, rref = ir->op2;
IRIns *irm;
if (lref != rref &&
((mayfuse(as, lref) && (irm = IR(lref), irm->o == IR_MUL) &&
ra_noreg(irm->r)) ||
(mayfuse(as, rref) && (irm = IR(rref), irm->o == IR_MUL) &&
(rref = lref, ai = air, ra_noreg(irm->r))))) {
Reg dest = ra_dest(as, ir, RSET_FPR);
Reg add = ra_hintalloc(as, rref, dest, RSET_FPR);
Reg left = ra_alloc2(as, irm,
rset_exclude(rset_exclude(RSET_FPR, dest), add));
Reg right = (left >> 8); left &= 255;
emit_dnma(as, ai, (dest & 31), (left & 31), (right & 31), (add & 31));
return 1;
}
return 0;
}
/* -- Calls --------------------------------------------------------------- */ /* -- Calls --------------------------------------------------------------- */
/* Generate a call to a C function. */ /* Generate a call to a C function. */
@ -1308,6 +1329,7 @@ static void asm_intmul(ASMState *as, IRIns *ir)
static void asm_add(ASMState *as, IRIns *ir) static void asm_add(ASMState *as, IRIns *ir)
{ {
if (irt_isnum(ir->t)) { if (irt_isnum(ir->t)) {
if (!asm_fusemadd(as, ir, A64I_FMADDd, A64I_FMADDd))
asm_fparith(as, ir, A64I_FADDd); asm_fparith(as, ir, A64I_FADDd);
return; return;
} }
@ -1317,6 +1339,7 @@ static void asm_add(ASMState *as, IRIns *ir)
static void asm_sub(ASMState *as, IRIns *ir) static void asm_sub(ASMState *as, IRIns *ir)
{ {
if (irt_isnum(ir->t)) { if (irt_isnum(ir->t)) {
if (!asm_fusemadd(as, ir, A64I_FNMSUBd, A64I_FMSUBd))
asm_fparith(as, ir, A64I_FSUBd); asm_fparith(as, ir, A64I_FSUBd);
return; return;
} }

View File

@ -74,6 +74,11 @@ static uint32_t emit_isfpk64(uint64_t n)
/* -- Emit basic instructions --------------------------------------------- */ /* -- Emit basic instructions --------------------------------------------- */
static void emit_dnma(ASMState *as, A64Ins ai, Reg rd, Reg rn, Reg rm, Reg ra)
{
*--as->mcp = ai | A64F_D(rd) | A64F_N(rn) | A64F_M(rm) | A64F_A(ra);
}
static void emit_dnm(ASMState *as, A64Ins ai, Reg rd, Reg rn, Reg rm) static void emit_dnm(ASMState *as, A64Ins ai, Reg rd, Reg rn, Reg rm)
{ {
*--as->mcp = ai | A64F_D(rd) | A64F_N(rn) | A64F_M(rm); *--as->mcp = ai | A64F_D(rd) | A64F_N(rn) | A64F_M(rm);