@@ -426,6 +426,165 @@ static void tcg_out_brcond2(TCGContext *s, const TCGArg *args,
tcg_out_label(s, label_next, (tcg_target_long)s->code_ptr);
}
+static void tcg_out_setcond(TCGContext *s, int cond, TCGArg arg0,
+ TCGArg arg1, TCGArg arg2, int const_arg2)
+{
+ int use_xor = (arg0 != arg1 && (const_arg2 || arg0 != arg2));
+
+ if (use_xor)
+ tcg_out_movi(s, TCG_TYPE_I32, arg0, 0);
+ tcg_out_cond(s, cond, arg1, arg2, const_arg2);
+ tcg_out_modrm(s, 0x90 | tcg_cond_to_jcc[cond] | P_EXT, 0, arg0);
+ if (!use_xor)
+ tgen_arithi(s, ARITH_AND, arg0, 0xff, 0);
+}
+
+static void tcg_out_setcond2(TCGContext *s, const TCGArg *args,
+ const int *const_args)
+{
+ TCGArg new_args[6];
+ int label_true, label_over;
+
+ memcpy(new_args, args+1, 5*sizeof(TCGArg));
+
+ if (args[0] == args[1] || args[0] == args[2]
+ || (!const_args[3] && args[0] == args[3])
+ || (!const_args[4] && args[0] == args[4])) {
+ /* When the destination overlaps with one of the argument
+ registers, don't do anything tricky. */
+ label_true = gen_new_label();
+ label_over = gen_new_label();
+
+ new_args[5] = label_true;
+ tcg_out_brcond2(s, new_args, const_args+1, 1);
+
+ tcg_out_movi(s, TCG_TYPE_I32, args[0], 0);
+ tcg_out_jxx(s, JCC_JMP, label_over, 1);
+ tcg_out_label(s, label_true, (tcg_target_long)s->code_ptr);
+
+ tcg_out_movi(s, TCG_TYPE_I32, args[0], 1);
+ tcg_out_label(s, label_over, (tcg_target_long)s->code_ptr);
+ } else {
+ /* When the destination does not overlap one of the arguments,
+ clear the destination first, jump if cond false, and emit an
+ increment in the true case. This results in smaller code. */
+
+ tcg_out_movi(s, TCG_TYPE_I32, args[0], 0);
+
+ label_over = gen_new_label();
+ new_args[4] = tcg_invert_cond(new_args[4]);
+ new_args[5] = label_over;
+ tcg_out_brcond2(s, new_args, const_args+1, 1);
+
+ tgen_arithi(s, ARITH_ADD, args[0], 1, 0);
+ tcg_out_label(s, label_over, (tcg_target_long)s->code_ptr);
+ }
+}
+
+static inline int have_cmov(void)
+{
+#ifdef __i686__
+ /* Compiler options say that cmov is available. */
+ return 1;
+#else
+ /* ??? Use cpuid or something and figure out what's running. */
+ return 0;
+#endif
+}
+
+static void tcg_out_movcond(TCGContext *s, const TCGArg *args,
+ const int *const_args)
+{
+ int vtc, vfc, cond, use_cmov = 0, do_swap = 0;
+ TCGArg d, vt, vf;
+
+ d = args[0];
+ vt = args[3];
+ vf = args[4];
+ vtc = const_args[3];
+ vfc = const_args[4];
+
+ /* ??? The jcc code path below assumes that one mov insn must be skipped.
+ Rather than complicate the code below, make sure to simplify the
+ conditional move here. */
+ if (vtc == vfc && vt == vf) {
+ if (vtc)
+ tcg_out_movi(s, TCG_TYPE_I32, d, vt);
+ else
+ tcg_out_mov(s, d, vt);
+ return;
+ }
+
+ cond = args[5];
+
+ /* If both arguments are constants, we *could* do all the funny bits that
+ gcc does with sbc, masks, etc. There's likely no point. Just use the
+ jcc version in this case. We also have to be careful about clobbering
+ inputs when trying to move constants into position. */
+
+ if (have_cmov()) {
+ use_cmov = 1;
+ if (vtc) {
+ if (vfc || d == vf)
+ use_cmov = 0;
+ else
+ do_swap = 1;
+ } else if (d == vt) {
+ if (vfc)
+ use_cmov = 0;
+ else
+ do_swap = 1;
+ }
+ }
+
+ if (!use_cmov) {
+ /* We're going to follow the lead of cmov and set D=VF first,
+ which means inverting the condition upon which we jump. */
+ cond = tcg_invert_cond(cond);
+
+ /* Don't allow the move we jump over to be a nop. */
+ do_swap = (!vtc && d == vt);
+ }
+
+ if (do_swap) {
+ TCGArg t;
+ cond = tcg_invert_cond(cond);
+ t = vf, vf = vt, vt = t;
+ t = vfc, vfc = vtc, vtc = t;
+ }
+
+ /* If possible, set D=0 before the compare, so that we can use XOR. */
+ if (vfc && vf == 0 && d != args[1] && (const_args[2] || d != args[2])) {
+ tcg_out_movi(s, TCG_TYPE_I32, d, 0);
+ vf = d, vfc = 0;
+ }
+
+ tcg_out_cond(s, cond, args[1], args[2], const_args[2]);
+
+ if (vfc) {
+ /* Force the use of "mov $0, d" to avoid clobbering flags. */
+ tcg_out8(s, 0xb8 + d);
+ tcg_out32(s, vf);
+ } else {
+ tcg_out_mov(s, d, vf);
+ }
+
+ if (use_cmov) {
+ assert (!vtc);
+ tcg_out_modrm(s, 0x40 | tcg_cond_to_jcc[cond] | P_EXT, d, vt);
+ } else {
+ int label_next = gen_new_label();
+
+ tcg_out_jxx(s, tcg_cond_to_jcc[cond], label_next, 1);
+ if (vtc)
+ tcg_out_movi(s, TCG_TYPE_I32, d, vt);
+ else
+ tcg_out_mov(s, d, vt);
+
+ tcg_out_label(s, label_next, (tcg_target_long)s->code_ptr);
+ }
+}
+
#if defined(CONFIG_SOFTMMU)
#include "../../softmmu_defs.h"
@@ -1087,6 +1246,16 @@ static inline void tcg_out_op(TCGContext *s, int opc,
tcg_out_modrm(s, 0xb7 | P_EXT, args[0], args[1]);
break;
+ case INDEX_op_setcond_i32:
+ tcg_out_setcond(s, args[3], args[0], args[1], args[2], const_args[2]);
+ break;
+ case INDEX_op_movcond_i32:
+ tcg_out_movcond(s, args, const_args);
+ break;
+ case INDEX_op_setcond2_i32:
+ tcg_out_setcond2(s, args, const_args);
+ break;
+
case INDEX_op_qemu_ld8u:
tcg_out_qemu_ld(s, args, 0);
break;
@@ -1175,6 +1344,10 @@ static const TCGTargetOpDef x86_op_defs[] = {
{ INDEX_op_ext8u_i32, { "r", "q"} },
{ INDEX_op_ext16u_i32, { "r", "r"} },
+ { INDEX_op_setcond_i32, { "q", "r", "ri" } },
+ { INDEX_op_movcond_i32, { "r", "r", "ri", "ri", "ri" } },
+ { INDEX_op_setcond2_i32, { "r", "r", "r", "ri", "ri" } },
+
#if TARGET_LONG_BITS == 32
{ INDEX_op_qemu_ld8u, { "r", "L" } },
{ INDEX_op_qemu_ld8s, { "r", "L" } },
Implement conditional moves in the i386 backend. Signed-off-by: Richard Henderson <rth@twiddle.net> --- tcg/i386/tcg-target.c | 173 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 173 insertions(+), 0 deletions(-)