target-arm: A64: Add fmov (scalar, immediate) instruction

This patch adds emulation for the fmov instruction working on scalars
with an immediate payload.

Signed-off-by: Alexander Graf <agraf@suse.de>
[WN: Commit message tweak, rebase and use new infrastructure.]
Signed-off-by: Will Newton <will.newton@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Alexander Graf 2014-01-04 22:15:50 +00:00 committed by Peter Maydell
parent 6a30667fb7
commit 6163f868c9

View File

@ -3479,7 +3479,37 @@ static void disas_fp_3src(DisasContext *s, uint32_t insn)
*/
static void disas_fp_imm(DisasContext *s, uint32_t insn)
{
unsupported_encoding(s, insn);
int rd = extract32(insn, 0, 5);
int imm8 = extract32(insn, 13, 8);
int is_double = extract32(insn, 22, 2);
uint64_t imm;
TCGv_i64 tcg_res;
if (is_double > 1) {
unallocated_encoding(s);
return;
}
/* The imm8 encodes the sign bit, enough bits to represent
* an exponent in the range 01....1xx to 10....0xx,
* and the most significant 4 bits of the mantissa; see
* VFPExpandImm() in the v8 ARM ARM.
*/
if (is_double) {
imm = (extract32(imm8, 7, 1) ? 0x8000 : 0) |
(extract32(imm8, 6, 1) ? 0x3fc0 : 0x4000) |
extract32(imm8, 0, 6);
imm <<= 48;
} else {
imm = (extract32(imm8, 7, 1) ? 0x8000 : 0) |
(extract32(imm8, 6, 1) ? 0x3e00 : 0x4000) |
(extract32(imm8, 0, 6) << 3);
imm <<= 16;
}
tcg_res = tcg_const_i64(imm);
write_fp_dreg(s, rd, tcg_res);
tcg_temp_free_i64(tcg_res);
}
/* C3.6.29 Floating point <-> fixed point conversions