Reviewed-by: Peter Maydell <[email protected]>
Signed-off-by: Richard Henderson <[email protected]>
---
target/arm/translate.c | 3 +--
target/arm/t16.decode | 17 +++++++++++++++++
2 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/target/arm/translate.c b/target/arm/translate.c
index b70491d39e..69092c12c3 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -10891,8 +10891,7 @@ static void disas_thumb_insn(DisasContext *s, uint32_t
insn)
case 15: /* IT, nop-hint. */
if ((insn & 0xf) == 0) {
- gen_nop_hint(s, (insn >> 4) & 0xf);
- break;
+ goto illegal_op; /* nop hint, in decodetree */
}
/*
* IT (If-Then)
diff --git a/target/arm/t16.decode b/target/arm/t16.decode
index 19a442b894..5829b9a58c 100644
--- a/target/arm/t16.decode
+++ b/target/arm/t16.decode
@@ -19,6 +19,7 @@
# This file is processed by scripts/decodetree.py
#
+&empty !extern
&s_rrr_shi !extern s rd rn rm shim shty
&s_rrr_shr !extern s rn rd rm rs shty
&s_rri_rot !extern s rn rd imm rot
@@ -204,3 +205,19 @@ SETEND 1011 0110 010 1 E:1 000 &setend
REV 1011 1010 00 ... ... @rdm
REV16 1011 1010 01 ... ... @rdm
REVSH 1011 1010 11 ... ... @rdm
+
+# Hints
+
+{
+ YIELD 1011 1111 0001 0000
+ WFE 1011 1111 0010 0000
+ WFI 1011 1111 0011 0000
+
+ # TODO: Implement SEV, SEVL; may help SMP performance.
+ # SEV 1011 1111 0100 0000
+ # SEVL 1011 1111 0101 0000
+
+ # The canonical nop has the second nibble as 0000, but the whole of the
+ # rest of the space is a reserved hint, behaves as nop.
+ NOP 1011 1111 ---- 0000
+}
--
2.17.1
