aboutsummaryrefslogtreecommitdiff
path: root/target
diff options
context:
space:
mode:
authorRichard Henderson <richard.henderson@linaro.org>2019-09-04 12:30:49 -0700
committerPeter Maydell <peter.maydell@linaro.org>2019-09-05 13:23:04 +0100
commit56e6250ede81b4e4b4ddb623874d6c3cdad4a96d (patch)
tree7ea77f1f93aa8f466801fd4fa8e28829efa893e2 /target
parentae3002b0218a90f2088817c70b35d3832ec91c18 (diff)
target/arm: Convert T16, nop hints
Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20190904193059.26202-60-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target')
-rw-r--r--target/arm/t16.decode17
-rw-r--r--target/arm/translate.c3
2 files changed, 18 insertions, 2 deletions
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
+}
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)