From 30feb7ee4387f40e73a1e938388b60d76c90fc4f Mon Sep 17 00:00:00 2001
From: Richard Henderson <richard.henderson@linaro.org>
Date: Sun, 2 Apr 2023 22:37:29 -0700
Subject: [PATCH] tcg/mips: Use full load/store helpers in user-only mode

Instead of using helper_unaligned_{ld,st}, use the full load/store helpers.
This will allow the fast path to increase alignment to implement atomicity
while not immediately raising an alignment exception.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/mips/tcg-target.c.inc | 57 ++-------------------------------------
 1 file changed, 2 insertions(+), 55 deletions(-)

diff --git a/tcg/mips/tcg-target.c.inc b/tcg/mips/tcg-target.c.inc
index 7770ef46bd..fa0f334e8d 100644
--- a/tcg/mips/tcg-target.c.inc
+++ b/tcg/mips/tcg-target.c.inc
@@ -1075,7 +1075,6 @@ static void tcg_out_call(TCGContext *s, const tcg_insn_unit *arg,
     tcg_out_nop(s);
 }
 
-#if defined(CONFIG_SOFTMMU)
 /* We have four temps, we might as well expose three of them. */
 static const TCGLdstHelperParam ldst_helper_param = {
     .ntmp = 3, .tmp = { TCG_TMP0, TCG_TMP1, TCG_TMP2 }
@@ -1088,8 +1087,7 @@ static bool tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
 
     /* resolve label address */
     if (!reloc_pc16(l->label_ptr[0], tgt_rx)
-        || (TCG_TARGET_REG_BITS < TARGET_LONG_BITS
-            && !reloc_pc16(l->label_ptr[1], tgt_rx))) {
+        || (l->label_ptr[1] && !reloc_pc16(l->label_ptr[1], tgt_rx))) {
         return false;
     }
 
@@ -1118,8 +1116,7 @@ static bool tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
 
     /* resolve label address */
     if (!reloc_pc16(l->label_ptr[0], tgt_rx)
-        || (TCG_TARGET_REG_BITS < TARGET_LONG_BITS
-            && !reloc_pc16(l->label_ptr[1], tgt_rx))) {
+        || (l->label_ptr[1] && !reloc_pc16(l->label_ptr[1], tgt_rx))) {
         return false;
     }
 
@@ -1139,56 +1136,6 @@ static bool tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
     return true;
 }
 
-#else
-static bool tcg_out_fail_alignment(TCGContext *s, TCGLabelQemuLdst *l)
-{
-    void *target;
-
-    if (!reloc_pc16(l->label_ptr[0], tcg_splitwx_to_rx(s->code_ptr))) {
-        return false;
-    }
-
-    if (TCG_TARGET_REG_BITS < TARGET_LONG_BITS) {
-        /* A0 is env, A1 is skipped, A2:A3 is the uint64_t address. */
-        TCGReg a2 = MIPS_BE ? l->addrhi_reg : l->addrlo_reg;
-        TCGReg a3 = MIPS_BE ? l->addrlo_reg : l->addrhi_reg;
-
-        if (a3 != TCG_REG_A2) {
-            tcg_out_mov(s, TCG_TYPE_I32, TCG_REG_A2, a2);
-            tcg_out_mov(s, TCG_TYPE_I32, TCG_REG_A3, a3);
-        } else if (a2 != TCG_REG_A3) {
-            tcg_out_mov(s, TCG_TYPE_I32, TCG_REG_A3, a3);
-            tcg_out_mov(s, TCG_TYPE_I32, TCG_REG_A2, a2);
-        } else {
-            tcg_out_mov(s, TCG_TYPE_I32, TCG_TMP0, TCG_REG_A2);
-            tcg_out_mov(s, TCG_TYPE_I32, TCG_REG_A2, TCG_REG_A3);
-            tcg_out_mov(s, TCG_TYPE_I32, TCG_REG_A3, TCG_TMP0);
-        }
-    } else {
-        tcg_out_mov(s, TCG_TYPE_TL, TCG_REG_A1, l->addrlo_reg);
-    }
-    tcg_out_mov(s, TCG_TYPE_PTR, TCG_REG_A0, TCG_AREG0);
-
-    /*
-     * Tail call to the helper, with the return address back inline.
-     * We have arrived here via BNEL, so $31 is already set.
-     */
-    target = (l->is_ld ? helper_unaligned_ld : helper_unaligned_st);
-    tcg_out_call_int(s, target, true);
-    return true;
-}
-
-static bool tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
-{
-    return tcg_out_fail_alignment(s, l);
-}
-
-static bool tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
-{
-    return tcg_out_fail_alignment(s, l);
-}
-#endif /* SOFTMMU */
-
 typedef struct {
     TCGReg base;
     MemOp align;