CRIS: Speedup btst by using a helper.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6203 c046a42c-6fe2-441c-8c8c-71466251a162

target-cris/helper.h

@@ -10,6 +10,8 @@ DEF_HELPER_0(rfn, void);
 DEF_HELPER_2(movl_sreg_reg, void, i32, i32)
 DEF_HELPER_2(movl_reg_sreg, void, i32, i32)
 
+DEF_HELPER_FLAGS_3(btst, TCG_CALL_PURE, i32, i32, i32, i32);
+
 DEF_HELPER_0(evaluate_flags_muls, void)
 DEF_HELPER_0(evaluate_flags_mulu, void)
 DEF_HELPER_0(evaluate_flags_mcp, void)

target-cris/op_helper.c

@@ -243,6 +243,32 @@ void helper_rfn(void)
     env->pregs[PR_CCS] |= M_FLAG;
 }
 
+uint32_t helper_btst(uint32_t t0, uint32_t t1, uint32_t ccs)
+{
+	/* FIXME: clean this up.  */
+
+	/* des ref:
+	   The N flag is set according to the selected bit in the dest reg.
+	   The Z flag is set if the selected bit and all bits to the right are
+	   zero.
+	   The X flag is cleared.
+	   Other flags are left untouched.
+	   The destination reg is not affected.*/
+	unsigned int fz, sbit, bset, mask, masked_t0;
+
+	sbit = t1 & 31;
+	bset = !!(t0 & (1 << sbit));
+	mask = sbit == 31 ? -1 : (1 << (sbit + 1)) - 1;
+	masked_t0 = t0 & mask;
+	fz = !(masked_t0 | bset);
+
+	/* Clear the X, N and Z flags.  */
+	ccs = ccs & ~(X_FLAG | N_FLAG | Z_FLAG);
+	/* Set the N and Z flags accordingly.  */
+	ccs |= (bset << 3) | (fz << 2);
+	return ccs;
+}
+
 static void evaluate_flags_writeback(uint32_t flags)
 {
 	unsigned int x, z, mask;

target-cris/translate.c

@@ -388,64 +388,6 @@ static void t_gen_lz_i32(TCGv d, TCGv x)
 	tcg_temp_free(n);
 }
 
-static void t_gen_btst(TCGv d, TCGv a, TCGv b)
-{
-        TCGv sbit;
-        TCGv bset;
-        TCGv t0;
-	int l1;
-
-        /* des ref:
-           The N flag is set according to the selected bit in the dest reg.
-           The Z flag is set if the selected bit and all bits to the right are
-           zero.
-           The X flag is cleared.
-           Other flags are left untouched.
-           The destination reg is not affected.
-
-        unsigned int fz, sbit, bset, mask, masked_t0;
-
-        sbit = T1 & 31;
-        bset = !!(T0 & (1 << sbit));
-        mask = sbit == 31 ? -1 : (1 << (sbit + 1)) - 1;
-        masked_t0 = T0 & mask;
-        fz = !(masked_t0 | bset);
-
-        // Clear the X, N and Z flags.
-        T0 = env->pregs[PR_CCS] & ~(X_FLAG | N_FLAG | Z_FLAG);
-        // Set the N and Z flags accordingly.
-        T0 |= (bset << 3) | (fz << 2);
-        */
-
-	l1 = gen_new_label();
-        sbit = tcg_temp_new();
-        bset = tcg_temp_new();
-        t0 = tcg_temp_new();
-
-        /* Compute bset and sbit.  */
-        tcg_gen_andi_tl(sbit, b, 31);
-        tcg_gen_shl_tl(t0, tcg_const_tl(1), sbit);
-        tcg_gen_and_tl(bset, a, t0);
-        tcg_gen_shr_tl(bset, bset, sbit);
-	/* Displace to N_FLAG.  */
-        tcg_gen_shli_tl(bset, bset, 3);
-
-        tcg_gen_shl_tl(sbit, tcg_const_tl(2), sbit);
-        tcg_gen_subi_tl(sbit, sbit, 1);
-        tcg_gen_and_tl(sbit, a, sbit);
-
-        tcg_gen_andi_tl(d, cpu_PR[PR_CCS], ~(X_FLAG | N_FLAG | Z_FLAG));
-	/* or in the N_FLAG.  */
-        tcg_gen_or_tl(d, d, bset);
-	tcg_gen_brcondi_tl(TCG_COND_NE, sbit, 0, l1);
-	/* or in the Z_FLAG.  */
-	tcg_gen_ori_tl(d, d, Z_FLAG);
-	gen_set_label(l1);
-
-        tcg_temp_free(sbit);
-        tcg_temp_free(bset);
-}
-
 static void t_gen_cris_dstep(TCGv d, TCGv a, TCGv b)
 {
 	int l1;
@@ -885,9 +827,6 @@ static void cris_alu_op_exec(DisasContext *dc, int op,
 		case CC_OP_LZ:
 			t_gen_lz_i32(dst, b);
 			break;
-		case CC_OP_BTST:
-			t_gen_btst(dst, a, b);
-			break;
 		case CC_OP_MULS:
 			t_gen_muls(dst, cpu_PR[PR_MOF], a, b);
 			break;
@@ -932,7 +871,7 @@ static void cris_alu(DisasContext *dc, int op,
 
 	writeback = 1;
 
-	if (op == CC_OP_BOUND || op == CC_OP_BTST)
+	if (op == CC_OP_BOUND)
 		tmp = tcg_temp_local_new();
 
 	if (op == CC_OP_CMP) {
@@ -1560,18 +1499,17 @@ static unsigned int dec_orq(DisasContext *dc)
 }
 static unsigned int dec_btstq(DisasContext *dc)
 {
-	TCGv l0;
 	dc->op1 = EXTRACT_FIELD(dc->ir, 0, 4);
 	DIS(fprintf (logfile, "btstq %u, $r%d\n", dc->op1, dc->op2));
 
 	cris_cc_mask(dc, CC_MASK_NZ);
-	l0 = tcg_temp_local_new();
+	cris_evaluate_flags(dc);
-	cris_alu(dc, CC_OP_BTST,
+	gen_helper_btst(cpu_PR[PR_CCS], cpu_R[dc->op2],
-		 l0, cpu_R[dc->op2], tcg_const_tl(dc->op1), 4);
+			tcg_const_tl(dc->op1), cpu_PR[PR_CCS]);
+	cris_alu(dc, CC_OP_MOVE,
+		 cpu_R[dc->op2], cpu_R[dc->op2], cpu_R[dc->op2], 4);
 	cris_update_cc_op(dc, CC_OP_FLAGS, 4);
-	t_gen_mov_preg_TN(dc, PR_CCS, l0);
 	dc->flags_uptodate = 1;
-	tcg_temp_free(l0);
 	return 2;
 }
 static unsigned int dec_asrq(DisasContext *dc)
@@ -2012,17 +1950,16 @@ static unsigned int dec_neg_r(DisasContext *dc)
 
 static unsigned int dec_btst_r(DisasContext *dc)
 {
-	TCGv l0;
 	DIS(fprintf (logfile, "btst $r%u, $r%u\n",
 		    dc->op1, dc->op2));
 	cris_cc_mask(dc, CC_MASK_NZ);
-
+	cris_evaluate_flags(dc);
-	l0 = tcg_temp_local_new();
+	gen_helper_btst(cpu_PR[PR_CCS], cpu_R[dc->op2],
-	cris_alu(dc, CC_OP_BTST, l0, cpu_R[dc->op2], cpu_R[dc->op1], 4);
+			cpu_R[dc->op1], cpu_PR[PR_CCS]);
+	cris_alu(dc, CC_OP_MOVE, cpu_R[dc->op2],
+		 cpu_R[dc->op2], cpu_R[dc->op2], 4);
 	cris_update_cc_op(dc, CC_OP_FLAGS, 4);
-	t_gen_mov_preg_TN(dc, PR_CCS, l0);
 	dc->flags_uptodate = 1;
-	tcg_temp_free(l0);
 	return 2;
 }