[Qemu-devel] [PATCH 2/4] tcg-arm: Use bic to implement and with constant

[Richard Henderson <rth@twiddle.net>]

This greatly improves the code we can produce for deposit
without armv7 support.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 tcg/arm/tcg-target.c | 38 +++++++++++++++++++++++++++++---------
 tcg/arm/tcg-target.h |  2 --
 2 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c
index 3422bd7..6618571 100644
--- a/tcg/arm/tcg-target.c
+++ b/tcg/arm/tcg-target.c
@@ -145,6 +145,9 @@ static void patch_reloc(uint8_t *code_ptr, int type,
     }
 }
 
+#define TCG_CT_CONST_ARM 0x100
+#define TCG_CT_CONST_INV 0x200
+
 /* parse target specific constraints */
 static int target_parse_constraint(TCGArgConstraint *ct, const char **pct_str)
 {
@@ -155,6 +158,9 @@ static int target_parse_constraint(TCGArgConstraint *ct, const char **pct_str)
     case 'I':
          ct->ct |= TCG_CT_CONST_ARM;
          break;
+    case 'K':
+         ct->ct |= TCG_CT_CONST_INV;
+         break;
 
     case 'r':
         ct->ct |= TCG_CT_REG;
@@ -275,16 +281,19 @@ static inline int check_fit_imm(uint32_t imm)
  * add, sub, eor...: ditto
  */
 static inline int tcg_target_const_match(tcg_target_long val,
-                const TCGArgConstraint *arg_ct)
+                                         const TCGArgConstraint *arg_ct)
 {
     int ct;
     ct = arg_ct->ct;
-    if (ct & TCG_CT_CONST)
+    if (ct & TCG_CT_CONST) {
         return 1;
-    else if ((ct & TCG_CT_CONST_ARM) && check_fit_imm(val))
+    } else if ((ct & TCG_CT_CONST_ARM) && check_fit_imm(val)) {
         return 1;
-    else
+    } else if ((ct & TCG_CT_CONST_INV) && check_fit_imm(~val)) {
+        return 1;
+    } else {
         return 0;
+    }
 }
 
 enum arm_data_opc_e {
@@ -1535,6 +1544,7 @@ static uint8_t *tb_ret_addr;
 static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
                 const TCGArg *args, const int *const_args)
 {
+    TCGArg a0, a1, a2;
     int c;
 
     switch (opc) {
@@ -1639,11 +1649,19 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
         c = ARITH_SUB;
         goto gen_arith;
     case INDEX_op_and_i32:
+        a0 = args[0], a1 = args[1], a2 = args[2];
         c = ARITH_AND;
-        goto gen_arith;
+        if (const_args[2] && check_fit_imm(~a2)) {
+            c = ARITH_BIC, a2 = ~a2;
+        }
+        goto gen_arith2;
     case INDEX_op_andc_i32:
+        a0 = args[0], a1 = args[1], a2 = args[2];
         c = ARITH_BIC;
-        goto gen_arith;
+        if (const_args[2] && check_fit_imm(~a2)) {
+            c = ARITH_AND, a2 = ~a2;
+        }
+        goto gen_arith2;
     case INDEX_op_or_i32:
         c = ARITH_ORR;
         goto gen_arith;
@@ -1651,7 +1669,9 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
         c = ARITH_EOR;
         /* Fall through.  */
     gen_arith:
-        tcg_out_dat_rI(s, COND_AL, c, args[0], args[1], args[2], const_args[2]);
+        a0 = args[0], a1 = args[1], a2 = args[2];
+    gen_arith2:
+        tcg_out_dat_rI(s, COND_AL, c, a0, a1, a2, const_args[2]);
         break;
     case INDEX_op_add2_i32:
         tcg_out_dat_reg2(s, COND_AL, ARITH_ADD, ARITH_ADC,
@@ -1836,8 +1856,8 @@ static const TCGTargetOpDef arm_op_defs[] = {
     { INDEX_op_mul_i32, { "r", "r", "r" } },
     { INDEX_op_mulu2_i32, { "r", "r", "r", "r" } },
     { INDEX_op_muls2_i32, { "r", "r", "r", "r" } },
-    { INDEX_op_and_i32, { "r", "r", "rI" } },
-    { INDEX_op_andc_i32, { "r", "r", "rI" } },
+    { INDEX_op_and_i32, { "r", "r", "rIK" } },
+    { INDEX_op_andc_i32, { "r", "r", "rIK" } },
     { INDEX_op_or_i32, { "r", "r", "rI" } },
     { INDEX_op_xor_i32, { "r", "r", "rI" } },
     { INDEX_op_neg_i32, { "r", "r" } },
diff --git a/tcg/arm/tcg-target.h b/tcg/arm/tcg-target.h
index cb89419..c4970d6 100644
--- a/tcg/arm/tcg-target.h
+++ b/tcg/arm/tcg-target.h
@@ -49,8 +49,6 @@ typedef enum {
 
 #define TCG_TARGET_NB_REGS 16
 
-#define TCG_CT_CONST_ARM 0x100
-
 /* used for function call generation */
 #define TCG_REG_CALL_STACK		TCG_REG_R13
 #define TCG_TARGET_STACK_ALIGN		8
-- 
1.8.1.2