https://gcc.gnu.org/g:b717c462b96e7870f8081d2bc330e4749a4b0538
commit r15-4307-gb717c462b96e7870f8081d2bc330e4749a4b0538
Author: Oleg Endo <olege...@gcc.gnu.org>
Date: Sun Oct 13 11:36:38 2024 +0900
SH: Fix cost estimation of mem load/store
For memory loads/stores (that contain a MEM rtx) sh_rtx_costs would wrongly
report a cost lower than 1 insn which is not accurate as it makes
loads/stores
appear cheaper than simple arithmetic insns. The cost of a load/store insn
is
at least 1 insn plus the cost of the address expression (some addressing
modes
can be considered more expensive than others due to additional constraints).
gcc/ChangeLog:
PR target/113533
* config/sh/sh.cc (sh_rtx_costs): Adjust cost estimation of MEM rtx
to be always at least COST_N_INSNS (1). Forward speed argument to
sh_address_cost.
Co-authored-by: Roger Sayle <ro...@nextmovesoftware.com>
Diff:
---
gcc/config/sh/sh.cc | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/gcc/config/sh/sh.cc b/gcc/config/sh/sh.cc
index 7391b8df5830..6ad202fd4263 100644
--- a/gcc/config/sh/sh.cc
+++ b/gcc/config/sh/sh.cc
@@ -3231,7 +3231,7 @@ multcosts (rtx x ATTRIBUTE_UNUSED)
static bool
sh_rtx_costs (rtx x, machine_mode mode ATTRIBUTE_UNUSED, int outer_code,
int opno ATTRIBUTE_UNUSED,
- int *total, bool speed ATTRIBUTE_UNUSED)
+ int *total, bool speed)
{
int code = GET_CODE (x);
@@ -3264,10 +3264,12 @@ sh_rtx_costs (rtx x, machine_mode mode
ATTRIBUTE_UNUSED, int outer_code,
}
return false;
- /* The cost of a mem access is mainly the cost of the address mode. */
+ /* The cost of a mem access is mainly the cost of the address mode on top
+ of the cost of the load/store insn itself. */
case MEM:
*total = sh_address_cost (XEXP (x, 0), GET_MODE (x), MEM_ADDR_SPACE (x),
- true);
+ speed)
+ + COSTS_N_INSNS (1);
return true;
case IF_THEN_ELSE:
@@ -3317,7 +3319,8 @@ sh_rtx_costs (rtx x, machine_mode mode ATTRIBUTE_UNUSED,
int outer_code,
{
*total = sh_address_cost (XEXP (XEXP (x, 0), 0),
GET_MODE (XEXP (x, 0)),
- MEM_ADDR_SPACE (XEXP (x, 0)), true);
+ MEM_ADDR_SPACE (XEXP (x, 0)), speed)
+ + COSTS_N_INSNS (1);
return true;
}
return false;
@@ -3335,7 +3338,8 @@ sh_rtx_costs (rtx x, machine_mode mode ATTRIBUTE_UNUSED,
int outer_code,
/* Handle SH2A's movu.b and movu.w insn. */
*total = sh_address_cost (XEXP (XEXP (x, 0), 0),
GET_MODE (XEXP (x, 0)),
- MEM_ADDR_SPACE (XEXP (x, 0)), true);
+ MEM_ADDR_SPACE (XEXP (x, 0)), speed)
+ + COSTS_N_INSNS (1);
return true;
}
return false;
@@ -3350,14 +3354,16 @@ sh_rtx_costs (rtx x, machine_mode mode
ATTRIBUTE_UNUSED, int outer_code,
{
*total = sh_address_cost (XEXP (XEXP (xx, 0), 0),
GET_MODE (XEXP (xx, 0)),
- MEM_ADDR_SPACE (XEXP (xx, 0)), true);
+ MEM_ADDR_SPACE (XEXP (xx, 0)), speed);
+ + COSTS_N_INSNS (1);
return true;
}
if (GET_CODE (xx) == SET && MEM_P (XEXP (xx, 1)))
{
*total = sh_address_cost (XEXP (XEXP (xx, 1), 0),
GET_MODE (XEXP (xx, 1)),
- MEM_ADDR_SPACE (XEXP (xx, 1)), true);
+ MEM_ADDR_SPACE (XEXP (xx, 1)), speed);
+ + COSTS_N_INSNS (1);
return true;
}
}
