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authorPeter Maydell <peter.maydell@linaro.org>2011-04-18 19:07:11 +0100
committerAurelien Jarno <aurelien@aurel32.net>2011-04-25 22:10:04 +0200
commit93262b1625ecb9c6ff22d5a51f38e312b5b7725a (patch)
tree6f9caaf68f4082c6e105c36d032220d941075a2f
parentdbf352ad6e55dc7b40c62b402289164265a4f17c (diff)
target-arm: Handle UNDEFs for Neon single element load/stores
Handle the UNDEF and UNPREDICTABLE cases for Neon "single element to one lane" VLD and "single element from one lane" VST. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
-rw-r--r--target-arm/translate.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/target-arm/translate.c b/target-arm/translate.c
index e1bda57e81..80b25ac5c4 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -3975,6 +3975,7 @@ static int disas_neon_ls_insn(CPUState * env, DisasContext *s, uint32_t insn)
stride = (1 << size) * nregs;
} else {
/* Single element. */
+ int idx = (insn >> 4) & 0xf;
pass = (insn >> 7) & 1;
switch (size) {
case 0:
@@ -3993,6 +3994,39 @@ static int disas_neon_ls_insn(CPUState * env, DisasContext *s, uint32_t insn)
abort();
}
nregs = ((insn >> 8) & 3) + 1;
+ /* Catch the UNDEF cases. This is unavoidably a bit messy. */
+ switch (nregs) {
+ case 1:
+ if (((idx & (1 << size)) != 0) ||
+ (size == 2 && ((idx & 3) == 1 || (idx & 3) == 2))) {
+ return 1;
+ }
+ break;
+ case 3:
+ if ((idx & 1) != 0) {
+ return 1;
+ }
+ /* fall through */
+ case 2:
+ if (size == 2 && (idx & 2) != 0) {
+ return 1;
+ }
+ break;
+ case 4:
+ if ((size == 2) && ((idx & 3) == 3)) {
+ return 1;
+ }
+ break;
+ default:
+ abort();
+ }
+ if ((rd + stride * (nregs - 1)) > 31) {
+ /* Attempts to write off the end of the register file
+ * are UNPREDICTABLE; we choose to UNDEF because otherwise
+ * the neon_load_reg() would write off the end of the array.
+ */
+ return 1;
+ }
addr = tcg_temp_new_i32();
load_reg_var(s, addr, rn);
for (reg = 0; reg < nregs; reg++) {