From: Alex Bennée <alex.ben...@linaro.org>
This actually covers two different sections of the encoding table:
Advanced SIMD scalar two-register miscellaneous FP16
Advanced SIMD two-register miscellaneous (FP16)
The difference between the two is covered by a combination of Q (bit
30) and S (bit 28). Notably the FRINTx instructions are only
available in the vector form.
This is just the decode skeleton which will be filled out by later
patches.
Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
Message-id: 20180227143852.11175-17-alex.ben...@linaro.org
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
---
target/arm/translate-a64.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 3487c0430f..9c1892c49a 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -11164,6 +11164,45 @@ static void disas_simd_two_reg_misc(DisasContext *s,
uint32_t insn)
}
}
+/* AdvSIMD [scalar] two register miscellaneous (FP16)
+ *
+ * 31 30 29 28 27 24 23 22 21 17 16 12 11 10 9 5 4 0
+ * +---+---+---+---+---------+---+-------------+--------+-----+------+------+
+ * | 0 | Q | U | S | 1 1 1 0 | a | 1 1 1 1 0 0 | opcode | 1 0 | Rn | Rd |
+ * +---+---+---+---+---------+---+-------------+--------+-----+------+------+
+ * mask: 1000 1111 0111 1110 0000 1100 0000 0000 0x8f7e 0c00
+ * val: 0000 1110 0111 1000 0000 1000 0000 0000 0x0e78 0800
+ *
+ * This actually covers two groups where scalar access is governed by
+ * bit 28. A bunch of the instructions (float to integral) only exist
+ * in the vector form and are un-allocated for the scalar decode. Also
+ * in the scalar decode Q is always 1.
+ */
+static void disas_simd_two_reg_misc_fp16(DisasContext *s, uint32_t insn)
+{
+ int fpop, opcode, a;
+
+ if (!arm_dc_feature(s, ARM_FEATURE_V8_FP16)) {
+ unallocated_encoding(s);
+ return;
+ }
+
+ if (!fp_access_check(s)) {
+ return;
+ }
+
+ opcode = extract32(insn, 12, 4);
+ a = extract32(insn, 23, 1);
+ fpop = deposit32(opcode, 5, 1, a);
+
+ switch (fpop) {
+ default:
+ fprintf(stderr, "%s: insn %#04x fpop %#2x\n", __func__, insn, fpop);
+ g_assert_not_reached();
+ }
+
+}
+
/* AdvSIMD scalar x indexed element
* 31 30 29 28 24 23 22 21 20 19 16 15 12 11 10 9 5 4 0
* +-----+---+-----------+------+---+---+------+-----+---+---+------+------+
@@ -12236,6 +12275,7 @@ static const AArch64DecodeTable data_proc_simd[] = {
{ 0xce800000, 0xffe00000, disas_crypto_xar },
{ 0xce408000, 0xffe0c000, disas_crypto_three_reg_imm2 },
{ 0x0e400400, 0x9f60c400, disas_simd_three_reg_same_fp16 },
+ { 0x0e780800, 0x8f7e0c00, disas_simd_two_reg_misc_fp16 },
{ 0x00000000, 0x00000000, NULL }
};
--
2.16.2
