From: Alistair Francis <alistair.francis@opensource.wdc.com>
To: qemu-devel@nongnu.org
Cc: alistair23@gmail.com, Philipp Tomsich <philipp.tomsich@vrull.eu>,
Richard Henderson <richard.henderson@linaro.org>,
Alistair Francis <alistair.francis@wdc.com>
Subject: [PULL 08/40] target/riscv: iterate over a table of decoders
Date: Sat, 12 Feb 2022 09:59:59 +1000 [thread overview]
Message-ID: <20220212000031.3946524-9-alistair.francis@opensource.wdc.com> (raw)
In-Reply-To: <20220212000031.3946524-1-alistair.francis@opensource.wdc.com>
From: Philipp Tomsich <philipp.tomsich@vrull.eu>
To split up the decoder into multiple functions (both to support
vendor-specific opcodes in separate files and to simplify maintenance
of orthogonal extensions), this changes decode_op to iterate over a
table of decoders predicated on guard functions.
This commit only adds the new structure and the table, allowing for
the easy addition of additional decoders in the future.
Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220202005249.3566542-6-philipp.tomsich@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
target/riscv/translate.c | 32 +++++++++++++++++++++++++++-----
1 file changed, 27 insertions(+), 5 deletions(-)
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index f19d5cd0c0..30b1b68341 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -111,6 +111,11 @@ static inline bool has_ext(DisasContext *ctx, uint32_t ext)
return ctx->misa_ext & ext;
}
+static bool always_true_p(DisasContext *ctx __attribute__((__unused__)))
+{
+ return true;
+}
+
#ifdef TARGET_RISCV32
#define get_xl(ctx) MXL_RV32
#elif defined(CONFIG_USER_ONLY)
@@ -855,15 +860,26 @@ static uint32_t opcode_at(DisasContextBase *dcbase, target_ulong pc)
static void decode_opc(CPURISCVState *env, DisasContext *ctx, uint16_t opcode)
{
- /* check for compressed insn */
+ /*
+ * A table with predicate (i.e., guard) functions and decoder functions
+ * that are tested in-order until a decoder matches onto the opcode.
+ */
+ static const struct {
+ bool (*guard_func)(DisasContext *);
+ bool (*decode_func)(DisasContext *, uint32_t);
+ } decoders[] = {
+ { always_true_p, decode_insn32 },
+ };
+
+ /* Check for compressed insn */
if (extract16(opcode, 0, 2) != 3) {
if (!has_ext(ctx, RVC)) {
gen_exception_illegal(ctx);
} else {
ctx->opcode = opcode;
ctx->pc_succ_insn = ctx->base.pc_next + 2;
- if (!decode_insn16(ctx, opcode)) {
- gen_exception_illegal(ctx);
+ if (decode_insn16(ctx, opcode)) {
+ return;
}
}
} else {
@@ -873,10 +889,16 @@ static void decode_opc(CPURISCVState *env, DisasContext *ctx, uint16_t opcode)
ctx->base.pc_next + 2));
ctx->opcode = opcode32;
ctx->pc_succ_insn = ctx->base.pc_next + 4;
- if (!decode_insn32(ctx, opcode32)) {
- gen_exception_illegal(ctx);
+
+ for (size_t i = 0; i < ARRAY_SIZE(decoders); ++i) {
+ if (decoders[i].guard_func(ctx) &&
+ decoders[i].decode_func(ctx, opcode32)) {
+ return;
+ }
}
}
+
+ gen_exception_illegal(ctx);
}
static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
--
2.34.1
next prev parent reply other threads:[~2022-02-12 0:11 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-11 23:59 [PULL 00/40] riscv-to-apply queue Alistair Francis
2022-02-11 23:59 ` [PULL 01/40] include: hw: remove ibex_plic.h Alistair Francis
2022-02-11 23:59 ` [PULL 02/40] Allow setting up to 8 bytes with the generic loader Alistair Francis
2022-02-11 23:59 ` [PULL 03/40] target/riscv: correct "code should not be reached" for x-rv128 Alistair Francis
2022-02-11 23:59 ` [PULL 04/40] target/riscv: refactor (anonymous struct) RISCVCPU.cfg into 'struct RISCVCPUConfig' Alistair Francis
2022-02-11 23:59 ` [PULL 05/40] target/riscv: riscv_tr_init_disas_context: copy pointer-to-cfg into cfg_ptr Alistair Francis
2022-02-11 23:59 ` [PULL 06/40] target/riscv: access configuration through cfg_ptr in DisasContext Alistair Francis
2022-02-11 23:59 ` [PULL 07/40] target/riscv: access cfg structure through DisasContext Alistair Francis
2022-02-11 23:59 ` Alistair Francis [this message]
2022-02-12 0:00 ` [PULL 09/40] target/riscv: Add XVentanaCondOps custom extension Alistair Francis
2022-02-12 0:00 ` [PULL 10/40] target/riscv: add a MAINTAINERS entry for XVentanaCondOps Alistair Francis
2022-02-12 0:00 ` [PULL 11/40] target/riscv: Fix vill field write in vtype Alistair Francis
2022-02-12 0:00 ` [PULL 12/40] target/riscv: Fix trap cause for RV32 HS-mode CSR access from RV64 HS-mode Alistair Francis
2022-02-12 0:00 ` [PULL 13/40] target/riscv: Implement SGEIP bit in hip and hie CSRs Alistair Francis
2022-02-12 0:00 ` [PULL 14/40] target/riscv: Implement hgeie and hgeip CSRs Alistair Francis
2022-02-12 0:00 ` [PULL 15/40] target/riscv: Improve delivery of guest external interrupts Alistair Francis
2022-02-12 0:00 ` [PULL 16/40] target/riscv: Allow setting CPU feature from machine/device emulation Alistair Francis
2022-02-12 0:00 ` [PULL 17/40] target/riscv: Add AIA cpu feature Alistair Francis
2022-02-12 0:00 ` [PULL 18/40] target/riscv: Add defines for AIA CSRs Alistair Francis
2022-02-12 0:00 ` [PULL 19/40] target/riscv: Allow AIA device emulation to set ireg rmw callback Alistair Francis
2022-02-12 0:00 ` [PULL 20/40] target/riscv: Implement AIA local interrupt priorities Alistair Francis
2022-02-12 0:00 ` [PULL 21/40] target/riscv: Implement AIA CSRs for 64 local interrupts on RV32 Alistair Francis
2022-02-12 0:00 ` [PULL 22/40] target/riscv: Implement AIA hvictl and hviprioX CSRs Alistair Francis
2022-02-12 0:00 ` [PULL 23/40] target/riscv: Implement AIA interrupt filtering CSRs Alistair Francis
2022-02-12 0:00 ` [PULL 24/40] target/riscv: Implement AIA mtopi, stopi, and vstopi CSRs Alistair Francis
2022-02-12 0:00 ` [PULL 25/40] target/riscv: Implement AIA xiselect and xireg CSRs Alistair Francis
2022-02-12 0:00 ` [PULL 26/40] target/riscv: Implement AIA IMSIC interface CSRs Alistair Francis
2022-02-12 0:00 ` [PULL 27/40] hw/riscv: virt: Use AIA INTC compatible string when available Alistair Francis
2022-02-12 0:00 ` [PULL 28/40] target/riscv: Allow users to force enable AIA CSRs in HART Alistair Francis
2022-02-12 0:00 ` [PULL 29/40] hw/intc: Add RISC-V AIA APLIC device emulation Alistair Francis
2022-02-12 0:00 ` [PULL 30/40] hw/riscv: virt: Add optional AIA APLIC support to virt machine Alistair Francis
2022-02-12 0:00 ` [PULL 31/40] hw/intc: Add RISC-V AIA IMSIC device emulation Alistair Francis
2022-02-12 0:00 ` [PULL 32/40] hw/riscv: virt: Add optional AIA IMSIC support to virt machine Alistair Francis
2022-02-12 0:00 ` [PULL 33/40] docs/system: riscv: Document AIA options for " Alistair Francis
2022-02-12 0:00 ` [PULL 34/40] hw/riscv: virt: Increase maximum number of allowed CPUs Alistair Francis
2022-02-12 0:00 ` [PULL 35/40] target/riscv: Ignore reserved bits in PTE for RV64 Alistair Francis
2022-02-12 0:00 ` [PULL 36/40] target/riscv: add PTE_A/PTE_D/PTE_U bits check for inner PTE Alistair Francis
2022-02-12 0:00 ` [PULL 37/40] target/riscv: add support for svnapot extension Alistair Francis
2022-02-12 0:00 ` [PULL 38/40] target/riscv: add support for svinval extension Alistair Francis
2022-02-12 0:00 ` [PULL 39/40] target/riscv: add support for svpbmt extension Alistair Francis
2022-02-12 0:00 ` [PULL 40/40] docs/system: riscv: Update description of CPU Alistair Francis
2022-02-15 11:39 ` [PULL 00/40] riscv-to-apply queue Peter Maydell
2022-02-16 6:28 ` Alistair Francis
2022-02-16 6:45 ` Anup Patel
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