CRIS: Use a helper for lz.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6205 c046a42c-6fe2-441c-8c8c-71466251a162

CRIS: Use a helper for lz.
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6205 c046a42c-6fe2-441c-8c8c-71466251a162
edgar_igl
1 parent 85220fba
Showing 3 changed files with 8 additions and 69 deletions
target-cris/helper.h
target-cris/op_helper.c
target-cris/translate.c
@@ -10,6 +10,7 @@ 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_1(lz, TCG_CALL_PURE, i32, i32);
 DEF_HELPER_FLAGS_3(btst, TCG_CALL_PURE, i32, i32, i32, i32);
 DEF_HELPER_0(evaluate_flags_muls, void)
@@ -23,6 +23,7 @@
 #include "exec.h"
 #include "mmu.h"
 #include "helper.h"
+#include "host-utils.h"
 #define D(x)
@@ -243,6 +244,11 @@ void helper_rfn(void)
     env->pregs[PR_CCS] |= M_FLAG;
 }
+uint32_t helper_lz(uint32_t t0)
+{
+	return clz32(t0);
+}
+
 uint32_t helper_btst(uint32_t t0, uint32_t t1, uint32_t ccs)
 {
 	/* FIXME: clean this up.  */
@@ -320,74 +320,6 @@ static void t_gen_mulu(TCGv d, TCGv d2, TCGv a, TCGv b)
 	tcg_temp_free_i64(t1);
 }
-/* 32bit branch-free binary search for counting leading zeros.  */
-static void t_gen_lz_i32(TCGv d, TCGv x)
-{
-	TCGv_i32 y, m, n;
-
-	y = tcg_temp_new_i32();
-	m = tcg_temp_new_i32();
-	n = tcg_temp_new_i32();
-
-	/* y = -(x >> 16)  */
-	tcg_gen_shri_i32(y, x, 16);
-	tcg_gen_neg_i32(y, y);
-
-	/* m = (y >> 16) & 16  */
-	tcg_gen_sari_i32(m, y, 16);
-	tcg_gen_andi_i32(m, m, 16);
-
-	/* n = 16 - m  */
-	tcg_gen_sub_i32(n, tcg_const_i32(16), m);
-	/* x = x >> m  */
-	tcg_gen_shr_i32(x, x, m);
-
-	/* y = x - 0x100  */
-	tcg_gen_subi_i32(y, x, 0x100);
-	/* m = (y >> 16) & 8  */
-	tcg_gen_sari_i32(m, y, 16);
-	tcg_gen_andi_i32(m, m, 8);
-	/* n = n + m  */
-	tcg_gen_add_i32(n, n, m);
-	/* x = x << m  */
-	tcg_gen_shl_i32(x, x, m);
-
-	/* y = x - 0x1000  */
-	tcg_gen_subi_i32(y, x, 0x1000);
-	/* m = (y >> 16) & 4  */
-	tcg_gen_sari_i32(m, y, 16);
-	tcg_gen_andi_i32(m, m, 4);
-	/* n = n + m  */
-	tcg_gen_add_i32(n, n, m);
-	/* x = x << m  */
-	tcg_gen_shl_i32(x, x, m);
-
-	/* y = x - 0x4000  */
-	tcg_gen_subi_i32(y, x, 0x4000);
-	/* m = (y >> 16) & 2  */
-	tcg_gen_sari_i32(m, y, 16);
-	tcg_gen_andi_i32(m, m, 2);
-	/* n = n + m  */
-	tcg_gen_add_i32(n, n, m);
-	/* x = x << m  */
-	tcg_gen_shl_i32(x, x, m);
-
-	/* y = x >> 14  */
-	tcg_gen_shri_i32(y, x, 14);
-	/* m = y & ~(y >> 1)  */
-	tcg_gen_sari_i32(m, y, 1);
-	tcg_gen_not_i32(m, m);
-	tcg_gen_and_i32(m, m, y);
-
-	/* d = n + 2 - m  */
-	tcg_gen_addi_i32(d, n, 2);
-	tcg_gen_sub_i32(d, d, m);
-
-	tcg_temp_free(y);
-	tcg_temp_free(m);
-	tcg_temp_free(n);
-}
-
 static void t_gen_cris_dstep(TCGv d, TCGv a, TCGv b)
 {
 	int l1;
@@ -825,7 +757,7 @@ static void cris_alu_op_exec(DisasContext *dc, int op,
 			t_gen_subx_carry(dc, dst);
 			break;
 		case CC_OP_LZ:
-			t_gen_lz_i32(dst, b);
+			gen_helper_lz(dst, b);
 			break;
 		case CC_OP_MULS:
 			t_gen_muls(dst, cpu_PR[PR_MOF], a, b);