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[AArch64 costs 14/18] Cost comparisons, flag setting operators and IF_THEN_ELSE

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gcc/

	* config/aarch64/aarch64.c (aarch64_rtx_costs): Cost comparison
	operators.


Co-Authored-By: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

From-SVN: r210506
This commit is contained in:
James Greenhalgh 2014-05-16 09:16:23 +00:00 • committed by James Greenhalgh
parent 4105fe3885
commit a8eecd00ec
2 changed files with 154 additions and 11 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2014-05-16 James Greenhalgh <james.greenhalgh@arm.com>
Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
* config/aarch64/aarch64.c (aarch64_rtx_costs): Cost comparison
operators.
2014-05-16 James Greenhalgh <james.greenhalgh@arm.com>
Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

159
gcc/config/aarch64/aarch64.c
View file

@ -4868,7 +4868,7 @@ static bool
aarch64_rtx_costs (rtx x, int code, int outer ATTRIBUTE_UNUSED,
int param ATTRIBUTE_UNUSED, int *cost, bool speed)
{
rtx op0, op1;
rtx op0, op1, op2;
const struct cpu_cost_table *extra_cost
= aarch64_tune_params->insn_extra_cost;
enum machine_mode mode = GET_MODE (x);
@ -5093,16 +5093,77 @@ aarch64_rtx_costs (rtx x, int code, int outer ATTRIBUTE_UNUSED,
goto cost_logic;
}
/* Comparisons can work if the order is swapped.
Canonicalization puts the more complex operation first, but
we want it in op1. */
if (! (REG_P (op0)
|| (GET_CODE (op0) == SUBREG && REG_P (SUBREG_REG (op0)))))
{
op0 = XEXP (x, 1);
op1 = XEXP (x, 0);
}
goto cost_minus;
if (GET_MODE_CLASS (GET_MODE (op0)) == MODE_INT)
{
/* TODO: A write to the CC flags possibly costs extra, this
needs encoding in the cost tables. */
/* CC_ZESWPmode supports zero extend for free. */
if (GET_MODE (x) == CC_ZESWPmode && GET_CODE (op0) == ZERO_EXTEND)
op0 = XEXP (op0, 0);
/* ANDS. */
if (GET_CODE (op0) == AND)
{
x = op0;
goto cost_logic;
}
if (GET_CODE (op0) == PLUS)
{
/* ADDS (and CMN alias). */
x = op0;
goto cost_plus;
}
if (GET_CODE (op0) == MINUS)
{
/* SUBS. */
x = op0;
goto cost_minus;
}
if (GET_CODE (op1) == NEG)
{
/* CMN. */
if (speed)
*cost += extra_cost->alu.arith;
*cost += rtx_cost (op0, COMPARE, 0, speed);
*cost += rtx_cost (XEXP (op1, 0), NEG, 1, speed);
return true;
}
/* CMP.
Compare can freely swap the order of operands, and
canonicalization puts the more complex operation first.
But the integer MINUS logic expects the shift/extend
operation in op1. */
if (! (REG_P (op0)
|| (GET_CODE (op0) == SUBREG && REG_P (SUBREG_REG (op0)))))
{
op0 = XEXP (x, 1);
op1 = XEXP (x, 0);
}
goto cost_minus;
}
if (GET_MODE_CLASS (GET_MODE (op0)) == MODE_FLOAT)
{
/* FCMP. */
if (speed)
*cost += extra_cost->fp[mode == DFmode].compare;
if (CONST_DOUBLE_P (op1) && aarch64_float_const_zero_rtx_p (op1))
{
/* FCMP supports constant 0.0 for no extra cost. */
return true;
}
return false;
}
return false;
case MINUS:
{
@ -5173,6 +5234,7 @@ cost_minus:
op0 = XEXP (x, 0);
op1 = XEXP (x, 1);
cost_plus:
if (GET_RTX_CLASS (GET_CODE (op0)) == RTX_COMPARE
|| GET_RTX_CLASS (GET_CODE (op0)) == RTX_COMM_COMPARE)
{
@ -5504,6 +5566,81 @@ cost_minus:
}
return false; /* All arguments need to be in registers. */
case IF_THEN_ELSE:
op2 = XEXP (x, 2);
op0 = XEXP (x, 0);
op1 = XEXP (x, 1);
if (GET_CODE (op1) == PC || GET_CODE (op2) == PC)
{
/* Conditional branch. */
if (GET_MODE_CLASS (GET_MODE (XEXP (op0, 0))) == MODE_CC)
return true;
else
{
if (GET_CODE (op0) == NE
|| GET_CODE (op0) == EQ)
{
rtx inner = XEXP (op0, 0);
rtx comparator = XEXP (op0, 1);
if (comparator == const0_rtx)
{
/* TBZ/TBNZ/CBZ/CBNZ. */
if (GET_CODE (inner) == ZERO_EXTRACT)
/* TBZ/TBNZ. */
*cost += rtx_cost (XEXP (inner, 0), ZERO_EXTRACT,
0, speed);
else
/* CBZ/CBNZ. */
*cost += rtx_cost (inner, GET_CODE (op0), 0, speed);
return true;
}
}
else if (GET_CODE (op0) == LT
|| GET_CODE (op0) == GE)
{
rtx comparator = XEXP (op0, 1);
/* TBZ/TBNZ. */
if (comparator == const0_rtx)
return true;
}
}
}
else if (GET_MODE_CLASS (GET_MODE (XEXP (op0, 0))) == MODE_CC)
{
/* It's a conditional operation based on the status flags,
so it must be some flavor of CSEL. */
/* CSNEG, CSINV, and CSINC are handled for free as part of CSEL. */
if (GET_CODE (op1) == NEG
|| GET_CODE (op1) == NOT
|| (GET_CODE (op1) == PLUS && XEXP (op1, 1) == const1_rtx))
op1 = XEXP (op1, 0);
*cost += rtx_cost (op1, IF_THEN_ELSE, 1, speed);
*cost += rtx_cost (op2, IF_THEN_ELSE, 2, speed);
return true;
}
/* We don't know what this is, cost all operands. */
return false;
case EQ:
case NE:
case GT:
case GTU:
case LT:
case LTU:
case GE:
case GEU:
case LE:
case LEU:
return false; /* All arguments must be in registers. */
default:
break;
}