Signed-off-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
tcg/loongarch64/tcg-target.c.inc | 137 +++++++++++++++++++++++++++++++
1 file changed, 137 insertions(+)
diff --git a/tcg/loongarch64/tcg-target.c.inc b/tcg/loongarch64/tcg-target.c.inc
index 615bed9096..bb45ea0fcf 100644
--- a/tcg/loongarch64/tcg-target.c.inc
+++ b/tcg/loongarch64/tcg-target.c.inc
@@ -247,6 +247,141 @@ static void tcg_out_mb(TCGContext *s, TCGArg a0)
tcg_out_opc_dbar(s, 0);
}
+static bool tcg_out_mov(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg)
+{
+ if (ret == arg) {
+ return true;
+ }
+ switch (type) {
+ case TCG_TYPE_I32:
+ case TCG_TYPE_I64:
+ /*
+ * Conventional register-register move used in LoongArch is
+ * `or dst, src, zero`.
+ */
+ tcg_out_opc_or(s, ret, arg, TCG_REG_ZERO);
+ break;
+ default:
+ g_assert_not_reached();
+ }
+ return true;
+}
+
+static bool imm_part_needs_loading(bool high_bits_are_ones,
+ tcg_target_long part)
+{
+ if (high_bits_are_ones) {
+ return part != -1;
+ } else {
+ return part != 0;
+ }
+}
+
+/* Loads a 32-bit immediate into rd, sign-extended. */
+static void tcg_out_movi_i32(TCGContext *s, TCGReg rd, int32_t val)
+{
+ tcg_target_long lo = sextreg(val, 0, 12);
+ tcg_target_long hi12 = sextreg(val, 12, 20);
+
+ /* Single-instruction cases. */
+ if (lo == val) {
+ /* val fits in simm12: addi.w rd, zero, val */
+ tcg_out_opc_addi_w(s, rd, TCG_REG_ZERO, val);
+ return;
+ }
+ if (0x800 <= val && val <= 0xfff) {
+ /* val fits in uimm12: ori rd, zero, val */
+ tcg_out_opc_ori(s, rd, TCG_REG_ZERO, val);
+ return;
+ }
+
+ /* High bits must be set; load with lu12i.w + optional ori. */
+ tcg_out_opc_lu12i_w(s, rd, hi12);
+ if (lo != 0) {
+ tcg_out_opc_ori(s, rd, rd, lo & 0xfff);
+ }
+}
+
+static void tcg_out_movi(TCGContext *s, TCGType type, TCGReg rd,
+ tcg_target_long val)
+{
+ /*
+ * LoongArch conventionally loads 64-bit immediates in at most 4 steps,
+ * with dedicated instructions for filling the respective bitfields
+ * below:
+ *
+ * 6 5 4 3
+ * 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2
+ * +-----------------------+---------------------------------------+...
+ * | hi52 | hi32 |
+ * +-----------------------+---------------------------------------+...
+ * 3 2 1
+ * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
+ * ...+-------------------------------------+-------------------------+
+ * | hi12 | lo |
+ * ...+-------------------------------------+-------------------------+
+ *
+ * Check if val belong to one of the several fast cases, before falling
+ * back to the slow path.
+ */
+
+ intptr_t pc_offset;
+ tcg_target_long val_lo, val_hi, pc_hi, offset_hi;
+ tcg_target_long hi32, hi52;
+ bool rd_high_bits_are_ones;
+
+ /* Value fits in signed i32. */
+ if (type == TCG_TYPE_I32 || val == (int32_t)val) {
+ tcg_out_movi_i32(s, rd, val);
+ return;
+ }
+
+ /* PC-relative cases. */
+ pc_offset = tcg_pcrel_diff(s, (void *)val);
+ if (pc_offset == sextreg(pc_offset, 0, 22) && (pc_offset & 3) == 0) {
+ /* Single pcaddu2i. */
+ tcg_out_opc_pcaddu2i(s, rd, pc_offset >> 2);
+ return;
+ }
+
+ if (pc_offset == (int32_t)pc_offset) {
+ /* Offset within 32 bits; load with pcalau12i + ori. */
+ val_lo = sextreg(val, 0, 12);
+ val_hi = val >> 12;
+ pc_hi = (val - pc_offset) >> 12;
+ offset_hi = val_hi - pc_hi;
+
+ tcg_debug_assert(offset_hi == sextreg(offset_hi, 0, 20));
+ tcg_out_opc_pcalau12i(s, rd, offset_hi);
+ if (val_lo != 0) {
+ tcg_out_opc_ori(s, rd, rd, val_lo & 0xfff);
+ }
+ return;
+ }
+
+ hi32 = sextreg(val, 32, 20);
+ hi52 = sextreg(val, 52, 12);
+
+ /* Single cu52i.d case. */
+ if (ctz64(val) >= 52) {
+ tcg_out_opc_cu52i_d(s, rd, TCG_REG_ZERO, hi52);
+ return;
+ }
+
+ /* Slow path. Initialize the low 32 bits, then concat high bits. */
+ tcg_out_movi_i32(s, rd, val);
+ rd_high_bits_are_ones = (int32_t)val < 0;
+
+ if (imm_part_needs_loading(rd_high_bits_are_ones, hi32)) {
+ tcg_out_opc_cu32i_d(s, rd, hi32);
+ rd_high_bits_are_ones = hi32 < 0;
+ }
+
+ if (imm_part_needs_loading(rd_high_bits_are_ones, hi52)) {
+ tcg_out_opc_cu52i_d(s, rd, rd, hi52);
+ }
+}
+
/*
* Entry-points
*/
@@ -262,6 +397,8 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc,
tcg_out_mb(s, a0);
break;
+ case INDEX_op_mov_i32: /* Always emitted via tcg_out_mov. */
+ case INDEX_op_mov_i64:
default:
g_assert_not_reached();
}
--
2.34.0