[Qemu-devel] [RFC] tcg: store constants without using registers when possible

[Aurelien Jarno]

Currently only implemented for x86/x86_64. It may also be implemented
for targets that keep one register for TCG internal use.

Signed-off-by: Aurelien Jarno <address@hidden>
---
 tcg/arm/tcg-target.c    |    6 ++++++
 tcg/hppa/tcg-target.c   |    6 ++++++
 tcg/i386/tcg-target.c   |    9 +++++++++
 tcg/ppc/tcg-target.c    |    9 +++++++++
 tcg/ppc64/tcg-target.c  |    9 +++++++++
 tcg/sparc/tcg-target.c  |    9 +++++++++
 tcg/tcg.c               |   10 ++++++----
 tcg/x86_64/tcg-target.c |   16 ++++++++++++++++
 8 files changed, 70 insertions(+), 4 deletions(-)

diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c
index f8d626d..339026f 100644
--- a/tcg/arm/tcg-target.c
+++ b/tcg/arm/tcg-target.c
@@ -1669,6 +1669,12 @@ static inline void tcg_out_st(TCGContext *s, TCGType 
type, int arg,
     tcg_out_st32(s, COND_AL, arg, arg1, arg2);
 }
 
+static inline int tcg_out_sti(TCGContext *s, TCGType type, tcg_target_long val,
+                              int arg1, tcg_target_long arg2)
+{
+    return 0;
+}
+
 static void tcg_out_addi(TCGContext *s, int reg, tcg_target_long val)
 {
     if (val > 0)
diff --git a/tcg/hppa/tcg-target.c b/tcg/hppa/tcg-target.c
index ddce60c..ba885b1 100644
--- a/tcg/hppa/tcg-target.c
+++ b/tcg/hppa/tcg-target.c
@@ -285,6 +285,12 @@ static inline void tcg_out_st(TCGContext *s, TCGType type, 
int ret,
     tcg_abort();
 }
 
+static inline int tcg_out_sti(TCGContext *s, TCGType type, tcg_target_long val,
+                              int arg1, tcg_target_long arg2)
+{
+    return 0;
+}
+
 static inline void tcg_out_arith(TCGContext *s, int t, int r1, int r2, int op)
 {
     tcg_out32(s, op | INSN_T(t) | INSN_R1(r1) | INSN_R2(r2));
diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
index b4e3b6f..d5494ce 100644
--- a/tcg/i386/tcg-target.c
+++ b/tcg/i386/tcg-target.c
@@ -276,6 +276,15 @@ static inline void tcg_out_st(TCGContext *s, TCGType type, 
int arg,
     tcg_out_modrm_offset(s, 0x89, arg, arg1, arg2);
 }
 
+static inline int tcg_out_sti(TCGContext *s, TCGType type, tcg_target_long val,
+                              int arg1, tcg_target_long arg2)
+{
+    /* movl */
+    tcg_out_modrm_offset(s, 0xc7, 0, arg1, arg2);
+    tcg_out32(s, val);
+    return 1;
+}
+
 static inline void tgen_arithi(TCGContext *s, int c, int r0, int32_t val, int 
cf)
 {
     if (!cf && ((c == ARITH_ADD && val == 1) || (c == ARITH_SUB && val == 
-1))) {
diff --git a/tcg/ppc/tcg-target.c b/tcg/ppc/tcg-target.c
index 07e6941..f23d375 100644
--- a/tcg/ppc/tcg-target.c
+++ b/tcg/ppc/tcg-target.c
@@ -958,6 +958,15 @@ static void tcg_out_st (TCGContext *s, TCGType type, int 
arg, int arg1,
     tcg_out_ldst (s, arg, arg1, arg2, STW, STWX);
 }
 
+static inline int tcg_out_sti(TCGContext *s, TCGType type, tcg_target_long val,
+                              int arg1, tcg_target_long arg2)
+{
+    /* movl */
+    tcg_out_modrm_offset(s, 0xc7, 0, arg1, arg2);
+    tcg_out32(s, val);
+    return 1;
+}
+
 static void ppc_addi (TCGContext *s, int rt, int ra, tcg_target_long si)
 {
     if (!si && rt == ra)
diff --git a/tcg/ppc64/tcg-target.c b/tcg/ppc64/tcg-target.c
index 1bb13e6..c44b7f5 100644
--- a/tcg/ppc64/tcg-target.c
+++ b/tcg/ppc64/tcg-target.c
@@ -917,6 +917,15 @@ static void tcg_out_st (TCGContext *s, TCGType type, int 
arg, int arg1,
         tcg_out_ldsta (s, arg, arg1, arg2, STD, STDX);
 }
 
+static inline int tcg_out_sti(TCGContext *s, TCGType type, tcg_target_long val,
+                              int arg1, tcg_target_long arg2)
+{
+    /* movl */
+    tcg_out_modrm_offset(s, 0xc7, 0, arg1, arg2);
+    tcg_out32(s, val);
+    return 1;
+}
+
 static void ppc_addi32 (TCGContext *s, int rt, int ra, tcg_target_long si)
 {
     if (!si && rt == ra)
diff --git a/tcg/sparc/tcg-target.c b/tcg/sparc/tcg-target.c
index 23cd9cd..c723576 100644
--- a/tcg/sparc/tcg-target.c
+++ b/tcg/sparc/tcg-target.c
@@ -392,6 +392,15 @@ static inline void tcg_out_st(TCGContext *s, TCGType type, 
int arg,
         tcg_out_ldst(s, arg, arg1, arg2, STX);
 }
 
+static inline int tcg_out_sti(TCGContext *s, TCGType type, tcg_target_long val,
+                              int arg1, tcg_target_long arg2)
+{
+    /* movl */
+    tcg_out_modrm_offset(s, 0xc7, 0, arg1, arg2);
+    tcg_out32(s, val);
+    return 1;
+}
+
 static inline void tcg_out_sety(TCGContext *s, tcg_target_long val)
 {
     if (val == 0 || val == -1)
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 93066e2..8818af3 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1385,12 +1385,14 @@ static void temp_save(TCGContext *s, int temp, 
TCGRegSet allocated_regs)
             ts->val_type = TEMP_VAL_MEM;
             break;
         case TEMP_VAL_CONST:
-            reg = tcg_reg_alloc(s, tcg_target_available_regs[ts->type], 
-                                allocated_regs);
             if (!ts->mem_allocated) 
                 temp_allocate_frame(s, temp);
-            tcg_out_movi(s, ts->type, reg, ts->val);
-            tcg_out_st(s, ts->type, reg, ts->mem_reg, ts->mem_offset);
+            if (!tcg_out_sti(s, ts->type, ts->val, ts->mem_reg, 
ts->mem_offset)) {
+                reg = tcg_reg_alloc(s, tcg_target_available_regs[ts->type],
+                                allocated_regs);
+                tcg_out_movi(s, ts->type, reg, ts->val);
+                tcg_out_st(s, ts->type, reg, ts->mem_reg, ts->mem_offset);
+            }
             ts->val_type = TEMP_VAL_MEM;
             break;
         case TEMP_VAL_MEM:
diff --git a/tcg/x86_64/tcg-target.c b/tcg/x86_64/tcg-target.c
index b4ba65f..f069347 100644
--- a/tcg/x86_64/tcg-target.c
+++ b/tcg/x86_64/tcg-target.c
@@ -395,6 +395,22 @@ static inline void tcg_out_st(TCGContext *s, TCGType type, 
int arg,
         tcg_out_modrm_offset(s, 0x89 | P_REXW, arg, arg1, arg2); /* movq */
 }
 
+static inline int tcg_out_sti(TCGContext *s, TCGType type, tcg_target_long val,
+                              int arg1, tcg_target_long arg2)
+{
+    if (type == TCG_TYPE_I32) {
+        tcg_out_modrm_offset(s, 0xc7, 0, arg1, arg2); /* movl */
+        tcg_out32(s, val);
+    } else {
+       if ((int32_t) val != val) {
+            return 0;
+        }
+        tcg_out_modrm_offset(s, 0xc7 | P_REXW, 0, arg1, arg2); /* movq */
+        tcg_out32(s, val);
+    }
+    return 1;
+}
+
 static inline void tgen_arithi32(TCGContext *s, int c, int r0, int32_t val)
 {
     if ((c == ARITH_ADD && val == 1) || (c == ARITH_SUB && val == -1)) {
-- 
1.6.4.3


-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
address@hidden                 http://www.aurel32.net