From 870e8d6348e62721704608be1d70c8704e2cdf3a Mon Sep 17 00:00:00 2001
From: Taylor Simpson <ltaylorsimpson@gmail.com>
Date: Wed, 12 Jun 2024 10:54:28 -0600
Subject: [PATCH] Hexagon (target/hexagon) optimize gen_read_greg

gregs 0-3 don't need special handling, so generate a TCG move
instead of calling a helper

Signed-off-by: Taylor Simpson <ltaylorsimpson@gmail.com>
---
 target/hexagon/genptr.c    | 12 ++++++++++--
 target/hexagon/op_helper.c |  8 ++++----
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/target/hexagon/genptr.c b/target/hexagon/genptr.c
index efaa9757acbe..adc8c8939717 100644
--- a/target/hexagon/genptr.c
+++ b/target/hexagon/genptr.c
@@ -344,12 +344,20 @@ static void gen_read_sreg_pair(TCGv_i64 dst, int reg_num)
 
 static void gen_read_greg(TCGv dst, int reg_num)
 {
-    gen_helper_greg_read(dst, tcg_env, tcg_constant_tl(reg_num));
+    if (reg_num <= HEX_GREG_G3) {
+        tcg_gen_mov_tl(dst, hex_greg[reg_num]);
+    } else {
+        gen_helper_greg_read(dst, tcg_env, tcg_constant_tl(reg_num));
+    }
 }
 
 static void gen_read_greg_pair(TCGv_i64 dst, int reg_num)
 {
-    gen_helper_greg_read_pair(dst, tcg_env, tcg_constant_tl(reg_num));
+    if (reg_num == HEX_GREG_G0 || reg_num == HEX_GREG_G2) {
+        tcg_gen_concat_i32_i64(dst, hex_greg[reg_num], hex_greg[reg_num + 1]);
+    } else {
+        gen_helper_greg_read_pair(dst, tcg_env, tcg_constant_tl(reg_num));
+    }
 }
 #endif
 
diff --git a/target/hexagon/op_helper.c b/target/hexagon/op_helper.c
index deab424964d8..d3e54932ed67 100644
--- a/target/hexagon/op_helper.c
+++ b/target/hexagon/op_helper.c
@@ -2412,16 +2412,16 @@ void HELPER(sreg_write_pair)(CPUHexagonState *env, uint32_t reg, uint64_t val)
 uint32_t HELPER(greg_read)(CPUHexagonState *env, uint32_t reg)
 
 {
+    /* Check should be done before calling this helper */
+    g_assert(reg > HEX_GREG_G3);
     return hexagon_greg_read(env, reg);
 }
 
 uint64_t HELPER(greg_read_pair)(CPUHexagonState *env, uint32_t reg)
 
 {
-    if (reg == HEX_GREG_G0 || reg == HEX_GREG_G2) {
-        return (uint64_t)(env->greg[reg]) |
-               (((uint64_t)(env->greg[reg + 1])) << 32);
-    }
+    /* Check should be done before calling this helper */
+    g_assert(reg > HEX_GREG_G3);
     switch (reg) {
     case HEX_GREG_GPCYCLELO: {
         target_ulong ssr = ARCH_GET_SYSTEM_REG(env, HEX_SREG_SSR);