target/mips: implement Octeon-specific BBIT instructions

This patch introduces Octeon-specific decoder and implements
check-bit-and-jump instructions.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <165572672705.167724.16667636081912075906.stgit@pasha-ThinkPad-X280>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
This commit is contained in:
Pavel Dovgalyuk 2022-06-20 15:05:27 +03:00 committed by Philippe Mathieu-Daudé
parent 72d680e408
commit 5e806fb002
2 changed files with 39 additions and 0 deletions

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@ -4,3 +4,12 @@
#
# SPDX-License-Identifier: LGPL-2.1-or-later
#
# Branch on bit set or clear
# BBIT0 110010 ..... ..... ................
# BBIT032 110110 ..... ..... ................
# BBIT1 111010 ..... ..... ................
# BBIT132 111110 ..... ..... ................
%bbit_p 28:1 16:5
BBIT 11 set:1 . 10 rs:5 ..... offset:16 p=%bbit_p

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@ -14,3 +14,33 @@
/* Include the auto-generated decoder. */
#include "decode-octeon.c.inc"
static bool trans_BBIT(DisasContext *ctx, arg_BBIT *a)
{
TCGv p;
if (ctx->hflags & MIPS_HFLAG_BMASK) {
LOG_DISAS("Branch in delay / forbidden slot at PC 0x"
TARGET_FMT_lx "\n", ctx->base.pc_next);
generate_exception_end(ctx, EXCP_RI);
return true;
}
/* Load needed operands */
TCGv t0 = tcg_temp_new();
gen_load_gpr(t0, a->rs);
p = tcg_constant_tl(1ULL << a->p);
if (a->set) {
tcg_gen_and_tl(bcond, p, t0);
} else {
tcg_gen_andc_tl(bcond, p, t0);
}
ctx->hflags |= MIPS_HFLAG_BC;
ctx->btarget = ctx->base.pc_next + 4 + a->offset * 4;
ctx->hflags |= MIPS_HFLAG_BDS32;
tcg_temp_free(t0);
return true;
}