tcg/arm: Fix constraints for sub

In 7536b82d288 we lost the rI constraint that allowed the use of
RSB to perform reg = imm - reg.  At the same time, drop support
for reg = reg - imm, which is now transformed generically to
addition, and need not be handled by the backend.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

diff --git a/tcg/arm/tcg-target-con-set.h b/tcg/arm/tcg-target-con-set.h
index 229ae258ac16dde29b08c1d9fadcf9fbe261a0e2..f46a8444fb008b938154391bf83c30d4b7365dac 100644 (file)
--- a/tcg/arm/tcg-target-con-set.h
+++ b/tcg/arm/tcg-target-con-set.h
@@ -30,6 +30,7 @@ C_O1_I2(r, r, rI)
 C_O1_I2(r, r, rIK)
 C_O1_I2(r, r, rIN)
 C_O1_I2(r, r, ri)
+C_O1_I2(r, rI, r)
 C_O1_I2(r, rZ, rZ)
 C_O1_I2(w, 0, w)
 C_O1_I2(w, w, w)

diff --git a/tcg/arm/tcg-target.c.inc b/tcg/arm/tcg-target.c.inc
index 8e9edeb7c624bfc59aa41fba85aef36d21a49e71..47c09ff2b197ba9b976dd172a2f320002a7de3bc 100644 (file)
--- a/tcg/arm/tcg-target.c.inc
+++ b/tcg/arm/tcg-target.c.inc
@@ -1984,12 +1984,8 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, TCGType type,
         break;
     case INDEX_op_sub_i32:
         if (const_args[1]) {
-            if (const_args[2]) {
-                tcg_out_movi32(s, COND_AL, args[0], args[1] - args[2]);
-            } else {
-                tcg_out_dat_rI(s, COND_AL, ARITH_RSB,
-                               args[0], args[2], args[1], 1);
-            }
+            tcg_out_dat_imm(s, COND_AL, ARITH_RSB,
+                            args[0], args[2], encode_imm_nofail(args[1]));
         } else {
             tcg_out_dat_rIN(s, COND_AL, ARITH_SUB, ARITH_ADD,
                             args[0], args[1], args[2], const_args[2]);
@@ -2234,10 +2230,11 @@ tcg_target_op_def(TCGOpcode op, TCGType type, unsigned flags)
     case INDEX_op_st_i32:
         return C_O0_I2(r, r);
 
-    case INDEX_op_sub_i32:
     case INDEX_op_setcond_i32:
     case INDEX_op_negsetcond_i32:
         return C_O1_I2(r, r, rIN);
+    case INDEX_op_sub_i32:
+        return C_O1_I2(r, rI, r);
 
     case INDEX_op_clz_i32:
     case INDEX_op_ctz_i32: