* [PATCH, i386]: Improve constant RTX costs a bit
@ 2016-05-20 17:42 Uros Bizjak
0 siblings, 0 replies; only message in thread
From: Uros Bizjak @ 2016-05-20 17:42 UTC (permalink / raw)
To: gcc-patches
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2016-05-20 Uros Bizjak <ubizjak@gmail.com>
* gcc/config/i386/i386.c (ix86_rtx_costs) <case CONST_DOUBLE>:
Use IS_STACK_MODE when calculating cost of standard 80387 constants.
Fallthru to CONST_VECTOR case to calculate cost of standard SSE
constants.
<case CONST_WIDE_INT>: Calculate cost of (MEM (SYMBOL_REF)).
(ix86_legitimate_constant_p): Use CASE_CONST_SCALAR_INT
and CASE_CONST_ANY.
Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.
Committed to mainline SVN.
Uros.
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diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index cecea11..26ec3cb 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -14864,8 +14864,7 @@ ix86_legitimate_constant_p (machine_mode mode, rtx x)
#endif
break;
- case CONST_INT:
- case CONST_WIDE_INT:
+ CASE_CONST_SCALAR_INT:
switch (mode)
{
case TImode:
@@ -14900,18 +14899,16 @@ ix86_legitimate_constant_p (machine_mode mode, rtx x)
static bool
ix86_cannot_force_const_mem (machine_mode mode, rtx x)
{
- /* We can always put integral constants and vectors in memory. */
+ /* We can put any immediate constant in memory. */
switch (GET_CODE (x))
{
- case CONST_INT:
- case CONST_WIDE_INT:
- case CONST_DOUBLE:
- case CONST_VECTOR:
+ CASE_CONST_ANY:
return false;
default:
break;
}
+
return !ix86_legitimate_constant_p (mode, x);
}
@@ -44073,43 +44070,43 @@ ix86_rtx_costs (rtx x, machine_mode mode, int outer_code_i, int opno,
*total = 0;
return true;
- case CONST_WIDE_INT:
- *total = 0;
- return true;
-
case CONST_DOUBLE:
- switch (standard_80387_constant_p (x))
+ if (TARGET_80387 && IS_STACK_MODE (mode))
+ switch (standard_80387_constant_p (x))
+ {
+ case -1:
+ case 0:
+ break;
+ case 1: /* 0.0 */
+ *total = 1;
+ return true;
+ default: /* Other constants */
+ *total = 2;
+ return true;
+ }
+ /* FALLTHRU */
+
+ case CONST_VECTOR:
+ switch (standard_sse_constant_p (x, mode))
{
- case 1: /* 0.0 */
- *total = 1;
- return true;
- default: /* Other constants */
- *total = 2;
- return true;
case 0:
- case -1:
break;
+ case 1: /* 0: xor eliminates false dependency */
+ *total = 0;
+ return true;
+ default: /* -1: cmp contains false dependency */
+ *total = 1;
+ return true;
}
- if (SSE_FLOAT_MODE_P (mode))
- {
- case CONST_VECTOR:
- switch (standard_sse_constant_p (x, mode))
- {
- case 0:
- break;
- case 1: /* 0: xor eliminates false dependency */
- *total = 0;
- return true;
- default: /* -1: cmp contains false dependency */
- *total = 1;
- return true;
- }
- }
+ /* FALLTHRU */
+
+ case CONST_WIDE_INT:
/* Fall back to (MEM (SYMBOL_REF)), since that's where
it'll probably end up. Add a penalty for size. */
*total = (COSTS_N_INSNS (1)
- + (flag_pic != 0 && !TARGET_64BIT)
- + (mode == SFmode ? 0 : mode == DFmode ? 1 : 2));
+ + (!TARGET_64BIT && flag_pic)
+ + (GET_MODE_SIZE (mode) <= 4
+ ? 0 : GET_MODE_SIZE (mode) <= 8 ? 1 : 2));
return true;
case ZERO_EXTEND:
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