tcg/arm: Handle ctz and clz opcodes

Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <rth@twiddle.net>
qemu · Jan 10, 2017 · cc0fec8 · cc0fec8
1 parent 53c76c1
commit cc0fec8
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Showing 2 changed files with 29 additions and 2 deletions.
diff --git a/tcg/arm/tcg-target.h b/tcg/arm/tcg-target.h
@@ -110,8 +110,8 @@ extern bool use_idiv_instructions;
 #define TCG_TARGET_HAS_eqv_i32          0
 #define TCG_TARGET_HAS_nand_i32         0
 #define TCG_TARGET_HAS_nor_i32          0
-#define TCG_TARGET_HAS_clz_i32          0
-#define TCG_TARGET_HAS_ctz_i32          0
+#define TCG_TARGET_HAS_clz_i32          use_armv5t_instructions
+#define TCG_TARGET_HAS_ctz_i32          use_armv7_instructions
 #define TCG_TARGET_HAS_deposit_i32      use_armv7_instructions
 #define TCG_TARGET_HAS_extract_i32      use_armv7_instructions
 #define TCG_TARGET_HAS_sextract_i32     use_armv7_instructions

diff --git a/tcg/arm/tcg-target.inc.c b/tcg/arm/tcg-target.inc.c
@@ -256,6 +256,9 @@ typedef enum {
     ARITH_BIC = 0xe << 21,
     ARITH_MVN = 0xf << 21,
 
+    INSN_CLZ       = 0x016f0f10,
+    INSN_RBIT      = 0x06ff0f30,
+
     INSN_LDR_IMM   = 0x04100000,
     INSN_LDR_REG   = 0x06100000,
     INSN_STR_IMM   = 0x04000000,
@@ -1829,6 +1832,28 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
         }
         break;
 
+    case INDEX_op_ctz_i32:
+        tcg_out_dat_reg(s, COND_AL, INSN_RBIT, TCG_REG_TMP, 0, args[1], 0);
+        a1 = TCG_REG_TMP;
+        goto do_clz;
+
+    case INDEX_op_clz_i32:
+        a1 = args[1];
+    do_clz:
+        a0 = args[0];
+        a2 = args[2];
+        c = const_args[2];
+        if (c && a2 == 32) {
+            tcg_out_dat_reg(s, COND_AL, INSN_CLZ, a0, 0, a1, 0);
+            break;
+        }
+        tcg_out_dat_imm(s, COND_AL, ARITH_CMP, 0, a1, 0);
+        tcg_out_dat_reg(s, COND_NE, INSN_CLZ, a0, 0, a1, 0);
+        if (c || a0 != a2) {
+            tcg_out_dat_rIK(s, COND_EQ, ARITH_MOV, ARITH_MVN, a0, 0, a2, c);
+        }
+        break;
+
     case INDEX_op_brcond_i32:
         tcg_out_dat_rIN(s, COND_AL, ARITH_CMP, ARITH_CMN, 0,
                        args[0], args[1], const_args[1]);
@@ -1963,6 +1988,8 @@ static const TCGTargetOpDef arm_op_defs[] = {
     { INDEX_op_sar_i32, { "r", "r", "ri" } },
     { INDEX_op_rotl_i32, { "r", "r", "ri" } },
     { INDEX_op_rotr_i32, { "r", "r", "ri" } },
+    { INDEX_op_clz_i32, { "r", "r", "rIK" } },
+    { INDEX_op_ctz_i32, { "r", "r", "rIK" } },
 
     { INDEX_op_brcond_i32, { "r", "rIN" } },
     { INDEX_op_setcond_i32, { "r", "r", "rIN" } },