lightning
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[PATCH v2 5/8] mips: Fill delay slots in jit_beqr / jit_beqi


From: Paul Cercueil
Subject: [PATCH v2 5/8] mips: Fill delay slots in jit_beqr / jit_beqi
Date: Mon, 9 Jan 2023 23:04:08 +0000

When we know that the last generated opcode is not the target of a jump,
and that it does not write to the source registers of the BEQ opcode, we
can swap it with the BEQ opcode, so that it now becomes the delay slot
of the BEQ opcode.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
 lib/jit_mips-cpu.c | 52 +++++++++++++++++++++++++++++++++++-----------
 lib/jit_mips.c     | 34 ++++++++++++++++++++++++++++--
 2 files changed, 72 insertions(+), 14 deletions(-)

diff --git a/lib/jit_mips-cpu.c b/lib/jit_mips-cpu.c
index ec2745b..65338b3 100644
--- a/lib/jit_mips-cpu.c
+++ b/lib/jit_mips-cpu.c
@@ -689,10 +689,10 @@ static jit_word_t 
_bler_u(jit_state_t*,jit_word_t,jit_int32_t,jit_int32_t);
 static jit_word_t _blei(jit_state_t*,jit_word_t,jit_int32_t,jit_word_t);
 #define blei_u(i0,r0,i1)               _blei_u(_jit,i0,r0,i1)
 static jit_word_t _blei_u(jit_state_t*,jit_word_t,jit_int32_t,jit_word_t);
-#define beqr(i0,r0,r1)                 _beqr(_jit,i0,r0,r1)
-static jit_word_t _beqr(jit_state_t*,jit_word_t,jit_int32_t,jit_int32_t);
-#define beqi(i0,r0,i1)                 _beqi(_jit,i0,r0,i1)
-static jit_word_t _beqi(jit_state_t*,jit_word_t,jit_int32_t,jit_word_t);
+#define beqr(i0,r0,r1,no_flag)         _beqr(_jit,i0,r0,r1,no_flag)
+static jit_word_t 
_beqr(jit_state_t*,jit_word_t,jit_int32_t,jit_int32_t,jit_bool_t);
+#define beqi(i0,r0,i1,no_flag)         _beqi(_jit,i0,r0,i1,no_flag)
+static jit_word_t 
_beqi(jit_state_t*,jit_word_t,jit_int32_t,jit_word_t,jit_bool_t);
 #define bger(i0,r0,r1)                 _bger(_jit,i0,r0,r1)
 static jit_word_t _bger(jit_state_t*,jit_word_t,jit_int32_t,jit_int32_t);
 #define bger_u(i0,r0,r1)               _bger_u(_jit,i0,r0,r1)
@@ -2313,32 +2313,60 @@ _blei_u(jit_state_t *_jit, jit_word_t i0, jit_int32_t 
r0, jit_word_t i1)
 }
 
 static jit_word_t
-_beqr(jit_state_t *_jit, jit_word_t i0, jit_int32_t r0, jit_int32_t r1)
+_beqr(jit_state_t *_jit, jit_word_t i0, jit_int32_t r0, jit_int32_t r1, 
jit_bool_t no_flag)
 {
     jit_word_t         w;
+    jit_int32_t                prev, offset;
+    jit_bool_t         swap_ds;
+
+    offset = ((jit_word_t)_jit->pc.ui - (jit_word_t)_jit->code.ptr) / 
sizeof(jit_instr_t);
+    swap_ds = no_flag
+           && (offset < 2 || !has_delay_slot((jit_instr_t)*(_jit->pc.ui - 2)))
+           && !op_writes_register((jit_instr_t)*(_jit->pc.ui - 1), r0)
+           && !op_writes_register((jit_instr_t)*(_jit->pc.ui - 1), r1);
+
+    if (swap_ds)
+       prev = *--_jit->pc.ui;
 
     w = _jit->pc.w;
     BEQ(r0, r1, ((i0 - w) >> 2) - 1);
-    NOP(1);
+    if (swap_ds)
+       ii(prev);
+    else
+       NOP(1);
 
     return (w);
 }
 
 static jit_word_t
-_beqi(jit_state_t *_jit, jit_word_t i0, jit_int32_t r0, jit_word_t i1)
+_beqi(jit_state_t *_jit, jit_word_t i0, jit_int32_t r0, jit_word_t i1, 
jit_bool_t no_flag)
 {
     jit_word_t         w;
-    jit_int32_t                reg;
+    jit_int32_t                reg, prev, offset;
+    jit_bool_t         swap_ds;
 
     if (i1 == 0) {
-       w = _jit->pc.w;
-       BEQ(r0, _ZERO_REGNO, ((i0 - w) >> 2) - 1);
-       NOP(1);
+       w = beqr(i0, r0, _ZERO_REGNO, no_flag);
     }
     else {
        reg = jit_get_reg(jit_class_gpr|jit_class_nospill);
+
+       swap_ds = no_flag
+               && (offset < 2 || !has_delay_slot((jit_instr_t)*(_jit->pc.ui - 
2)))
+               && !op_writes_register((jit_instr_t)*(_jit->pc.ui - 1), r0);
+
+       if (swap_ds)
+               prev = *--_jit->pc.ui;
+
        movi(rn(reg), i1);
-       w = beqr(i0, r0, rn(reg));
+       w = _jit->pc.w;
+       BEQ(r0, rn(reg), ((i0 - w) >> 2) - 1);
+
+       if (swap_ds)
+               ii(prev);
+       else
+               NOP(1);
+
        jit_unget_reg(reg);
     }
 
diff --git a/lib/jit_mips.c b/lib/jit_mips.c
index cf917aa..518a540 100644
--- a/lib/jit_mips.c
+++ b/lib/jit_mips.c
@@ -1253,6 +1253,21 @@ _emit_code(jit_state_t *_jit)
                    patch(word, node);                                  \
                }                                                       \
                break
+#define case_brrn(name, type, no_flag)                                 \
+           case jit_code_##name##r##type:                              \
+               temp = node->u.n;                                       \
+               assert(temp->code == jit_code_label ||                  \
+                      temp->code == jit_code_epilog);                  \
+               if (temp->flag & jit_flag_patch)                        \
+                   name##r##type(temp->u.w, rn(node->v.w),             \
+                                 rn(node->w.w), no_flag);              \
+               else {                                                  \
+                   word = name##r##type(_jit->pc.w,                    \
+                                        rn(node->v.w), rn(node->w.w),  \
+                                        no_flag);                      \
+                   patch(word, node);                                  \
+               }                                                       \
+               break
 #define case_brw(name, type)                                           \
            case jit_code_##name##i##type:                              \
                temp = node->u.n;                                       \
@@ -1267,6 +1282,21 @@ _emit_code(jit_state_t *_jit)
                    patch(word, node);                                  \
                }                                                       \
                break
+#define case_brwn(name, type, no_flag)                                 \
+           case jit_code_##name##i##type:                              \
+               temp = node->u.n;                                       \
+               assert(temp->code == jit_code_label ||                  \
+                      temp->code == jit_code_epilog);                  \
+               if (temp->flag & jit_flag_patch)                        \
+                   name##i##type(temp->u.w,                            \
+                                 rn(node->v.w), node->w.w, no_flag);   \
+               else {                                                  \
+                   word = name##i##type(_jit->pc.w,                    \
+                                        rn(node->v.w), node->w.w,      \
+                                        no_flag);                      \
+                   patch(word, node);                                  \
+               }                                                       \
+               break
 #define case_brf(name, type, size)                                     \
            case jit_code_##name##i##type:                              \
                temp = node->u.n;                                       \
@@ -1489,8 +1519,8 @@ _emit_code(jit_state_t *_jit)
                case_brw(ble,);
                case_brr(ble, _u);
                case_brw(ble, _u);
-               case_brr(beq,);
-               case_brw(beq,);
+               case_brrn(beq,, no_flag);
+               case_brwn(beq,, no_flag);
                case_brr(bge,);
                case_brw(bge,);
                case_brr(bge, _u);
-- 
2.39.0




reply via email to

[Prev in Thread] Current Thread [Next in Thread]