From 9876d50eb3286cd2b53c92d5ea409b8b228586c3 Mon Sep 17 00:00:00 2001
From: YunQiang Su <syq@gcc.gnu.org>
Date: Sat, 30 Dec 2023 01:34:28 +0800
Subject: [PATCH] MIPS: Implement TARGET_INSN_COSTS
When combine some instructions, the generic `rtx_cost`
may over estimate the cost of result RTL, due to that
the RTL may be quite complex and `rtx_cost` has no
information that this RTL can be convert to simple
hardware instruction(s).
In this case, Let's use `insn_count * perf_ratio` to
estimate the cost if both of them are available.
Otherwise fallback to pattern_cost.
When non-speed, Let's use the length as cost.
gcc
* config/mips/mips.cc (mips_insn_cost): New function.
gcc/testsuite
* gcc.target/mips/data-sym-multi-pool.c: Skip Os or -O0.
---
gcc/config/mips/mips.cc | 33 +++++++++++++++++++
.../gcc.target/mips/data-sym-multi-pool.c | 2 +-
2 files changed, 34 insertions(+), 1 deletion(-)
diff --git a/gcc/config/mips/mips.cc b/gcc/config/mips/mips.cc
index 3131749d6eae..46b7d9b64fff 100644
--- a/gcc/config/mips/mips.cc
+++ b/gcc/config/mips/mips.cc
@@ -4170,6 +4170,37 @@ mips_set_reg_reg_cost (machine_mode mode)
}
}
+/* Implement TARGET_INSN_COSTS. */
+
+static int
+mips_insn_cost (rtx_insn *x, bool speed)
+{
+ int cost;
+ int count;
+ int ratio;
+
+ if (recog_memoized (x) < 0
+ && GET_CODE (PATTERN (x)) != ASM_INPUT
+ && asm_noperands (PATTERN (x)) < 0)
+ goto pattern_cost;
+
+ /* FIXME: return get_attr_length? More tests may be needed. */
+ if (!speed)
+ goto pattern_cost;
+
+ count = get_attr_insn_count (x);
+ ratio = get_attr_perf_ratio (x);
+ cost = count * ratio;
+ if (cost > 0)
+ return cost;
+
+pattern_cost:
+ cost = pattern_cost (PATTERN (x), speed);
+ /* If the cost is zero, then it's likely a complex insn.
+ FIXME: Return COSTS_N_INSNS (2)? More tests are needed. */
+ return cost;
+}
+
/* Implement TARGET_RTX_COSTS. */
static bool
@@ -23069,6 +23100,8 @@ mips_bit_clear_p (enum machine_mode mode, unsigned HOST_WIDE_INT m)
#define TARGET_RTX_COSTS mips_rtx_costs
#undef TARGET_ADDRESS_COST
#define TARGET_ADDRESS_COST mips_address_cost
+#undef TARGET_INSN_COST
+#define TARGET_INSN_COST mips_insn_cost
#undef TARGET_NO_SPECULATION_IN_DELAY_SLOTS_P
#define TARGET_NO_SPECULATION_IN_DELAY_SLOTS_P mips_no_speculation_in_delay_slots_p
diff --git a/gcc/testsuite/gcc.target/mips/data-sym-multi-pool.c b/gcc/testsuite/gcc.target/mips/data-sym-multi-pool.c
index 3cf2d4f0248b..8643095ff9ff 100644
--- a/gcc/testsuite/gcc.target/mips/data-sym-multi-pool.c
+++ b/gcc/testsuite/gcc.target/mips/data-sym-multi-pool.c
@@ -1,6 +1,6 @@
/* { dg-do compile } */
/* { dg-options "-mips16 -mcode-readable=yes -fno-tree-vrp -fno-tree-dominator-opts" } */
-/* { dg-skip-if "per-function expected output" { *-*-* } { "-flto" } { "" } } */
+/* { dg-skip-if "per-function expected output" { *-*-* } { "-flto" "-O0" "-Os" } { "" } } */
/* This testcase generates multiple constant pools within a function body. */
--
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