The sextract operation is genereted only when the corresponding Wasm
instructions are available, as specified by TCG_TARGET_sextract_valid.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 tcg/wasm/tcg-target-has.h |  5 +++++
 tcg/wasm/tcg-target.c.inc | 42 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/tcg/wasm/tcg-target-has.h b/tcg/wasm/tcg-target-has.h
index 7e3caf8790..cfb85388de 100644
--- a/tcg/wasm/tcg-target-has.h
+++ b/tcg/wasm/tcg-target-has.h
@@ -4,4 +4,9 @@
 
 #define TCG_TARGET_HAS_tst 0
 
+#define TCG_TARGET_extract_valid(type, ofs, len) 0
+#define TCG_TARGET_sextract_valid(type, ofs, len) \
+    ((ofs == 0) && ((len == 8) || (len == 16) || (len == 32)))
+#define TCG_TARGET_deposit_valid(type, ofs, len) 0
+
 #endif
diff --git a/tcg/wasm/tcg-target.c.inc b/tcg/wasm/tcg-target.c.inc
index 70de3bbf83..dd75deecd3 100644
--- a/tcg/wasm/tcg-target.c.inc
+++ b/tcg/wasm/tcg-target.c.inc
@@ -182,7 +182,10 @@ typedef enum {
     OPC_I64_SHR_U = 0x88,
 
     OPC_I32_WRAP_I64 = 0xa7,
+    OPC_I64_EXTEND_I32_S = 0xac,
     OPC_I64_EXTEND_I32_U = 0xad,
+    OPC_I64_EXTEND8_S = 0xc2,
+    OPC_I64_EXTEND16_S = 0xc3,
 } WasmInsn;
 
 typedef enum {
@@ -391,6 +394,33 @@ static void tcg_wasm_out_movcond(TCGContext *s, TCGType type, TCGReg ret,
     tcg_wasm_out_op_idx(s, OPC_GLOBAL_SET, REG_IDX(ret));
 }
 
+static void tcg_wasm_out_sextract(TCGContext *s, TCGReg dest, TCGReg arg1,
+                                  int pos, int len)
+{
+    tcg_wasm_out_op_idx(s, OPC_GLOBAL_GET, REG_IDX(arg1));
+
+    if (pos == 0) {
+        switch (len) {
+        case 8:
+            tcg_wasm_out_op(s, OPC_I64_EXTEND8_S);
+            break;
+        case 16:
+            tcg_wasm_out_op(s, OPC_I64_EXTEND16_S);
+            break;
+        case 32:
+            tcg_wasm_out_op(s, OPC_I32_WRAP_I64);
+            tcg_wasm_out_op(s, OPC_I64_EXTEND_I32_S);
+            break;
+        default:
+            g_assert_not_reached();
+        }
+    } else {
+        g_assert_not_reached();
+    }
+
+    tcg_wasm_out_op_idx(s, OPC_GLOBAL_SET, REG_IDX(dest));
+}
+
 static void tcg_out_op_rr(TCGContext *s, TCGOpcode op, TCGReg r0, TCGReg r1)
 {
     tcg_insn_unit_tci insn = 0;
@@ -529,6 +559,18 @@ static const TCGOutOpBinary outop_mul = {
     .out_rrr = tgen_mul,
 };
 
+static void tcg_out_sextract(TCGContext *s, TCGType type, TCGReg rd,
+                             TCGReg rs, unsigned pos, unsigned len)
+{
+    tcg_out_op_rrbb(s, INDEX_op_sextract, rd, rs, pos, len);
+    tcg_wasm_out_sextract(s, rd, rs, pos, len);
+}
+
+static const TCGOutOpExtract outop_sextract = {
+    .base.static_constraint = C_O1_I1(r, r),
+    .out_rr = tcg_out_sextract,
+};
+
 static void tgen_shl(TCGContext *s, TCGType type,
                      TCGReg a0, TCGReg a1, TCGReg a2)
 {
-- 
2.43.0