[v2,15/16] target/xtensa: implement const16

Commit Message

Max Filippov Dec. 19, 2017, 5:38 a.m. UTC

const16 is an opcode that shifts 16 lower bits of an address register
to the 16 upper bits and puts its immediate operand into the lower 16
bits. It is not controlled by an Xtensa option and doesn't have a fixed
opcode.

Signed-off-by: Max Filippov <[e-mail]>
---
Changes v1->v2:
- reimplement translate_const16 using tcg_gen_deposit_i32.

 target/xtensa/translate.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

Patch

diff --git a/target/xtensa/translate.c b/target/xtensa/translate.c
index a84bbf3bedc3..bf299dbf9a04 100644
--- a/target/xtensa/translate.c
+++ b/target/xtensa/translate.c
@@ -1526,6 +1526,17 @@  static void translate_clrb_expstate(DisasContext *dc, const uint32_t arg[],
     tcg_gen_andi_i32(cpu_UR[EXPSTATE], cpu_UR[EXPSTATE], ~(1u << arg[0]));
 }
 
+static void translate_const16(DisasContext *dc, const uint32_t arg[],
+                             const uint32_t par[])
+{
+    if (gen_window_check1(dc, arg[0])) {
+        TCGv_i32 c = tcg_const_i32(arg[1]);
+
+        tcg_gen_deposit_i32(cpu_R[arg[0]], c, cpu_R[arg[0]], 16, 16);
+        tcg_temp_free(c);
+    }
+}
+
 /* par[0]: privileged, par[1]: check memory access */
 static void translate_dcache(DisasContext *dc, const uint32_t arg[],
                              const uint32_t par[])
@@ -2742,6 +2753,9 @@  static const XtensaOpcodeOps core_ops[] = {
         .name = "clrb_expstate",
         .translate = translate_clrb_expstate,
     }, {
+        .name = "const16",
+        .translate = translate_const16,
+    }, {
         .name = "depbits",
         .translate = translate_depbits,
     }, {