On 2026/08/26 10:38 AM, Chinmay Rath wrote: > From: Aboorva Devarajan <[email protected]> > > Move below instructions to decodetree specification: > > lwat, stwat : X-form (word atomic, ISA 3.0) > ldat, stdat : X-form (doubleword atomic, ISA 3.0) > > The legacy gen_ld_atomic()/gen_st_atomic() functions that read register > fields and the function code from ctx->opcode are replaced by new > do_ld_atomic()/do_st_atomic() helpers in fixedpoint-impl.c.inc that > use the pre-extracted decodetree argument fields (a->rt, a->ra, a->rb) > directly. The RB field carries the Function Code (FC) selecting the > atomic operation. > > gen_fetch_inc_conditional() is similarly moved and refactored to accept > the destination register number as an explicit parameter instead of > extracting it from ctx->opcode. > > Checked with '-d in_asm,op'. The printed TCG ops may differ from the > pre-refactor log because EA now uses do_ea_calc(ctx, ra, 0), which lowers > as GPR[ra] + 0 (then narrow in 32-bit mode) instead of mov/ext32u from ra > alone. > > Signed-off-by: Aboorva Devarajan <[email protected]> > Reviewed-by: Nikhil Kumar Singh <[email protected]> > Reviewed-by: Glenn Miles <[email protected]> > Signed-off-by: Chinmay Rath <[email protected]> > --- > target/ppc/insn32.decode | 7 + > target/ppc/translate.c | 212 -------------------- > target/ppc/translate/fixedpoint-impl.c.inc | 215 +++++++++++++++++++++ > 3 files changed, 222 insertions(+), 212 deletions(-) > > diff --git a/target/ppc/insn32.decode b/target/ppc/insn32.decode > index 8425c70b9d..a1c2f549bd 100644 > --- a/target/ppc/insn32.decode > +++ b/target/ppc/insn32.decode > @@ -343,6 +343,13 @@ LSKU 111010 ..... ..... ............. 0 11 > @DD > LCXU 111010 ..... ..... ............. 1 11 @DD > > > +### Fixed-Point Atomic Load/Store Instructions > + > +LWAT 011111 ..... ..... ..... 1001000110 - @X > +STWAT 011111 ..... ..... ..... 1011000110 - @X > +LDAT 011111 ..... ..... ..... 1001100110 - @X > +STDAT 011111 ..... ..... ..... 1011100110 - @X > + > ### Fixed-Point Store Instructions > > STB 100110 ..... ..... ................ @D > diff --git a/target/ppc/translate.c b/target/ppc/translate.c > index 548a7c0437..179cb69dc5 100644 > --- a/target/ppc/translate.c > +++ b/target/ppc/translate.c > @@ -2741,212 +2741,6 @@ static void gen_isync(DisasContext *ctx) > ctx->base.is_jmp = DISAS_EXIT_UPDATE; > } > > -static void gen_fetch_inc_conditional(DisasContext *ctx, MemOp memop, > - TCGv EA, TCGCond cond, int addend) > -{ > - TCGv t = tcg_temp_new(); > - TCGv t2 = tcg_temp_new(); > - TCGv u = tcg_temp_new(); > - > - tcg_gen_qemu_ld_tl(t, EA, ctx->mem_idx, memop); > - tcg_gen_addi_tl(t2, EA, memop_size(memop)); > - tcg_gen_qemu_ld_tl(t2, t2, ctx->mem_idx, memop); > - tcg_gen_addi_tl(u, t, addend); > - > - /* E.g. for fetch and increment bounded... */ > - /* mem(EA,s) = (t != t2 ? u = t + 1 : t) */ > - tcg_gen_movcond_tl(cond, u, t, t2, u, t); > - tcg_gen_qemu_st_tl(u, EA, ctx->mem_idx, memop); > - > - /* RT = (t != t2 ? t : u = 1<<(s*8-1)) */ > - tcg_gen_movcond_tl(cond, cpu_gpr[rD(ctx->opcode)], t, t2, t, > - tcg_constant_tl(1 << (memop_size(memop) * 8 - 1))); > -} > - > -static void gen_ld_atomic(DisasContext *ctx, MemOp memop) > -{ > - uint32_t gpr_FC = FC(ctx->opcode); > - TCGv EA = tcg_temp_new(); > - int rt = rD(ctx->opcode); > - bool need_serial; > - TCGv src, dst; > - > - gen_addr_register(ctx, EA); > - dst = cpu_gpr[rt]; > - src = cpu_gpr[(rt + 1) & 31]; > - > - need_serial = false; > - memop |= MO_ALIGN; > - switch (gpr_FC) { > - case 0: /* Fetch and add */ > - tcg_gen_atomic_fetch_add_tl(dst, EA, src, ctx->mem_idx, memop); > - break; > - case 1: /* Fetch and xor */ > - tcg_gen_atomic_fetch_xor_tl(dst, EA, src, ctx->mem_idx, memop); > - break; > - case 2: /* Fetch and or */ > - tcg_gen_atomic_fetch_or_tl(dst, EA, src, ctx->mem_idx, memop); > - break; > - case 3: /* Fetch and 'and' */ > - tcg_gen_atomic_fetch_and_tl(dst, EA, src, ctx->mem_idx, memop); > - break; > - case 4: /* Fetch and max unsigned */ > - tcg_gen_atomic_fetch_umax_tl(dst, EA, src, ctx->mem_idx, memop); > - break; > - case 5: /* Fetch and max signed */ > - tcg_gen_atomic_fetch_smax_tl(dst, EA, src, ctx->mem_idx, memop); > - break; > - case 6: /* Fetch and min unsigned */ > - tcg_gen_atomic_fetch_umin_tl(dst, EA, src, ctx->mem_idx, memop); > - break; > - case 7: /* Fetch and min signed */ > - tcg_gen_atomic_fetch_smin_tl(dst, EA, src, ctx->mem_idx, memop); > - break; > - case 8: /* Swap */ > - tcg_gen_atomic_xchg_tl(dst, EA, src, ctx->mem_idx, memop); > - break; > - > - case 16: /* Compare and swap not equal */ > - if (tb_cflags(ctx->base.tb) & CF_PARALLEL) { > - need_serial = true; > - } else { > - TCGv t0 = tcg_temp_new(); > - TCGv t1 = tcg_temp_new(); > - > - tcg_gen_qemu_ld_tl(t0, EA, ctx->mem_idx, memop); > - if ((memop & MO_SIZE) == MO_64 || TARGET_LONG_BITS == 32) { > - tcg_gen_mov_tl(t1, src); > - } else { > - tcg_gen_ext32u_tl(t1, src); > - } > - tcg_gen_movcond_tl(TCG_COND_NE, t1, t0, t1, > - cpu_gpr[(rt + 2) & 31], t0); > - tcg_gen_qemu_st_tl(t1, EA, ctx->mem_idx, memop); > - tcg_gen_mov_tl(dst, t0); > - } > - break; > - > - case 24: /* Fetch and increment bounded */ > - if (tb_cflags(ctx->base.tb) & CF_PARALLEL) { > - need_serial = true; > - } else { > - gen_fetch_inc_conditional(ctx, memop, EA, TCG_COND_NE, 1); > - } > - break; > - case 25: /* Fetch and increment equal */ > - if (tb_cflags(ctx->base.tb) & CF_PARALLEL) { > - need_serial = true; > - } else { > - gen_fetch_inc_conditional(ctx, memop, EA, TCG_COND_EQ, 1); > - } > - break; > - case 28: /* Fetch and decrement bounded */ > - if (tb_cflags(ctx->base.tb) & CF_PARALLEL) { > - need_serial = true; > - } else { > - gen_fetch_inc_conditional(ctx, memop, EA, TCG_COND_NE, -1); > - } > - break; > - > - default: > - /* invoke data storage error handler */ > - gen_exception_err(ctx, POWERPC_EXCP_DSI, POWERPC_EXCP_INVAL); > - } > - > - if (need_serial) { > - /* Restart with exclusive lock. */ > - gen_helper_exit_atomic(tcg_env); > - ctx->base.is_jmp = DISAS_NORETURN; > - } > -} > - > -static void gen_lwat(DisasContext *ctx) > -{ > - gen_ld_atomic(ctx, DEF_MEMOP(MO_UL)); > -} > - > -#ifdef TARGET_PPC64 > -static void gen_ldat(DisasContext *ctx) > -{ > - gen_ld_atomic(ctx, DEF_MEMOP(MO_UQ)); > -} > -#endif > - > -static void gen_st_atomic(DisasContext *ctx, MemOp memop) > -{ > - uint32_t gpr_FC = FC(ctx->opcode); > - TCGv EA = tcg_temp_new(); > - TCGv src, discard; > - > - gen_addr_register(ctx, EA); > - src = cpu_gpr[rD(ctx->opcode)]; > - discard = tcg_temp_new(); > - > - memop |= MO_ALIGN; > - switch (gpr_FC) { > - case 0: /* add and Store */ > - tcg_gen_atomic_add_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > - break; > - case 1: /* xor and Store */ > - tcg_gen_atomic_xor_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > - break; > - case 2: /* Or and Store */ > - tcg_gen_atomic_or_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > - break; > - case 3: /* 'and' and Store */ > - tcg_gen_atomic_and_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > - break; > - case 4: /* Store max unsigned */ > - tcg_gen_atomic_umax_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > - break; > - case 5: /* Store max signed */ > - tcg_gen_atomic_smax_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > - break; > - case 6: /* Store min unsigned */ > - tcg_gen_atomic_umin_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > - break; > - case 7: /* Store min signed */ > - tcg_gen_atomic_smin_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > - break; > - case 24: /* Store twin */ > - if (tb_cflags(ctx->base.tb) & CF_PARALLEL) { > - /* Restart with exclusive lock. */ > - gen_helper_exit_atomic(tcg_env); > - ctx->base.is_jmp = DISAS_NORETURN; > - } else { > - TCGv t = tcg_temp_new(); > - TCGv t2 = tcg_temp_new(); > - TCGv s = tcg_temp_new(); > - TCGv s2 = tcg_temp_new(); > - TCGv ea_plus_s = tcg_temp_new(); > - > - tcg_gen_qemu_ld_tl(t, EA, ctx->mem_idx, memop); > - tcg_gen_addi_tl(ea_plus_s, EA, memop_size(memop)); > - tcg_gen_qemu_ld_tl(t2, ea_plus_s, ctx->mem_idx, memop); > - tcg_gen_movcond_tl(TCG_COND_EQ, s, t, t2, src, t); > - tcg_gen_movcond_tl(TCG_COND_EQ, s2, t, t2, src, t2); > - tcg_gen_qemu_st_tl(s, EA, ctx->mem_idx, memop); > - tcg_gen_qemu_st_tl(s2, ea_plus_s, ctx->mem_idx, memop); > - } > - break; > - default: > - /* invoke data storage error handler */ > - gen_exception_err(ctx, POWERPC_EXCP_DSI, POWERPC_EXCP_INVAL); > - } > -} > - > -static void gen_stwat(DisasContext *ctx) > -{ > - gen_st_atomic(ctx, DEF_MEMOP(MO_UL)); > -} > - > -#ifdef TARGET_PPC64 > -static void gen_stdat(DisasContext *ctx) > -{ > - gen_st_atomic(ctx, DEF_MEMOP(MO_UQ)); > -} > -#endif > - > /* wait */ > static void gen_wait(DisasContext *ctx) > { > @@ -5584,12 +5378,6 @@ GEN_HANDLER(lswx, 0x1F, 0x15, 0x10, 0x00000001, > PPC_STRING), > GEN_HANDLER(stswi, 0x1F, 0x15, 0x16, 0x00000001, PPC_STRING), > GEN_HANDLER(stswx, 0x1F, 0x15, 0x14, 0x00000001, PPC_STRING), > GEN_HANDLER(isync, 0x13, 0x16, 0x04, 0x03FFF801, PPC_MEM), > -GEN_HANDLER_E(lwat, 0x1F, 0x06, 0x12, 0x00000001, PPC_NONE, PPC2_ISA300), > -GEN_HANDLER_E(stwat, 0x1F, 0x06, 0x16, 0x00000001, PPC_NONE, PPC2_ISA300), > -#if defined(TARGET_PPC64) > -GEN_HANDLER_E(ldat, 0x1F, 0x06, 0x13, 0x00000001, PPC_NONE, PPC2_ISA300), > -GEN_HANDLER_E(stdat, 0x1F, 0x06, 0x17, 0x00000001, PPC_NONE, PPC2_ISA300), > -#endif > /* ISA v3.0 changed the extended opcode from 62 to 30 */ > GEN_HANDLER(wait, 0x1F, 0x1E, 0x01, 0x039FF801, PPC_WAIT), > GEN_HANDLER_E(wait, 0x1F, 0x1E, 0x00, 0x039CF801, PPC_NONE, PPC2_ISA300), > diff --git a/target/ppc/translate/fixedpoint-impl.c.inc > b/target/ppc/translate/fixedpoint-impl.c.inc > index 25a60d3d3a..4d35133adc 100644 > --- a/target/ppc/translate/fixedpoint-impl.c.inc > +++ b/target/ppc/translate/fixedpoint-impl.c.inc > @@ -1646,3 +1646,218 @@ static bool trans_SRAWI(DisasContext *ctx, arg_SRAWI > *a) > } > return true; > } > + > +static void do_fetch_inc_conditional(DisasContext *ctx, MemOp memop, > + TCGv EA, int rt, > + TCGCond cond, int addend) > +{ > + TCGv t = tcg_temp_new(); > + TCGv t2 = tcg_temp_new(); > + TCGv u = tcg_temp_new(); > + > + tcg_gen_qemu_ld_tl(t, EA, ctx->mem_idx, memop); > + tcg_gen_addi_tl(t2, EA, memop_size(memop)); > + tcg_gen_qemu_ld_tl(t2, t2, ctx->mem_idx, memop); > + tcg_gen_addi_tl(u, t, addend); > + > + /* mem(EA,s) = (t cond t2 ? u = t + addend : t) */ > + tcg_gen_movcond_tl(cond, u, t, t2, u, t); > + tcg_gen_qemu_st_tl(u, EA, ctx->mem_idx, memop); > + > + /* RT = (t cond t2 ? t : 1<<(s*8-1)) */ > + tcg_gen_movcond_tl(cond, cpu_gpr[rt], t, t2, t, > + tcg_constant_tl(1 << (memop_size(memop) * 8 - 1))); > +} > + > +/* > + * Fixed-Point Atomic Load/Store Instructions > + * > + * In the X-form encoding the RB field carries the Function Code (FC) > + * that selects the atomic operation. EA is computed from RA alone. > + */ > +static bool do_ld_atomic(DisasContext *ctx, arg_X *a, MemOp memop) > +{ > + TCGv EA, dst, src; > + bool need_serial; > + > + REQUIRE_INSNS_FLAGS2(ctx, ISA300); > + > + EA = do_ea_calc(ctx, a->ra, tcg_constant_tl(0)); > + dst = cpu_gpr[a->rt]; > + src = cpu_gpr[(a->rt + 1) & 31]; > + > + need_serial = false; > + memop |= MO_ALIGN; > + switch (a->rb) { > + case 0: /* Fetch and add */ > + tcg_gen_atomic_fetch_add_tl(dst, EA, src, ctx->mem_idx, memop); > + break; > + case 1: /* Fetch and xor */ > + tcg_gen_atomic_fetch_xor_tl(dst, EA, src, ctx->mem_idx, memop); > + break; > + case 2: /* Fetch and or */ > + tcg_gen_atomic_fetch_or_tl(dst, EA, src, ctx->mem_idx, memop); > + break; > + case 3: /* Fetch and 'and' */ > + tcg_gen_atomic_fetch_and_tl(dst, EA, src, ctx->mem_idx, memop); > + break; > + case 4: /* Fetch and max unsigned */ > + tcg_gen_atomic_fetch_umax_tl(dst, EA, src, ctx->mem_idx, memop); > + break; > + case 5: /* Fetch and max signed */ > + tcg_gen_atomic_fetch_smax_tl(dst, EA, src, ctx->mem_idx, memop); > + break; > + case 6: /* Fetch and min unsigned */ > + tcg_gen_atomic_fetch_umin_tl(dst, EA, src, ctx->mem_idx, memop); > + break; > + case 7: /* Fetch and min signed */ > + tcg_gen_atomic_fetch_smin_tl(dst, EA, src, ctx->mem_idx, memop); > + break; > + case 8: /* Swap */ > + tcg_gen_atomic_xchg_tl(dst, EA, src, ctx->mem_idx, memop); > + break; > + > + case 16: /* Compare and swap not equal */ > + if (tb_cflags(ctx->base.tb) & CF_PARALLEL) { > + need_serial = true; > + } else { > + TCGv t0 = tcg_temp_new(); > + TCGv t1 = tcg_temp_new(); > + > + tcg_gen_qemu_ld_tl(t0, EA, ctx->mem_idx, memop); > + if ((memop & MO_SIZE) == MO_64 || TARGET_LONG_BITS == 32) { > + tcg_gen_mov_tl(t1, src); > + } else { > + tcg_gen_ext32u_tl(t1, src); > + } > + tcg_gen_movcond_tl(TCG_COND_NE, t1, t0, t1, > + cpu_gpr[(a->rt + 2) & 31], t0); > + tcg_gen_qemu_st_tl(t1, EA, ctx->mem_idx, memop); > + tcg_gen_mov_tl(dst, t0); > + } > + break; > + > + case 24: /* Fetch and increment bounded */ > + if (tb_cflags(ctx->base.tb) & CF_PARALLEL) { > + need_serial = true; > + } else { > + do_fetch_inc_conditional(ctx, memop, EA, a->rt, TCG_COND_NE, 1); > + } > + break; > + case 25: /* Fetch and increment equal */ > + if (tb_cflags(ctx->base.tb) & CF_PARALLEL) { > + need_serial = true; > + } else { > + do_fetch_inc_conditional(ctx, memop, EA, a->rt, TCG_COND_EQ, 1); > + } > + break; > + case 28: /* Fetch and decrement bounded */ > + if (tb_cflags(ctx->base.tb) & CF_PARALLEL) { > + need_serial = true; > + } else { > + do_fetch_inc_conditional(ctx, memop, EA, a->rt, TCG_COND_NE, -1); > + } > + break; > + > + default: > + /* invoke data storage error handler */ > + gen_exception_err(ctx, POWERPC_EXCP_DSI, POWERPC_EXCP_INVAL); > + return true;
Nit: This bypasses the need_serial block (harmless since gen_exception_err sets DISAS_NORETURN), but it's inconsistent with do_st_atomic which falls through to the final return true. The early return true here is unnecessary — dropping it makes both functions structurally uniform and keeps a single exit point. Otherwise, LGTM. Reviewed-by: Amit Machhiwal <[email protected]> > + } > + > + if (need_serial) { > + /* Restart with exclusive lock. */ > + gen_helper_exit_atomic(tcg_env); > + ctx->base.is_jmp = DISAS_NORETURN; > + } > + return true; > +} > + > +static bool do_st_atomic(DisasContext *ctx, arg_X *a, MemOp memop) > +{ > + TCGv EA, src, discard; > + > + REQUIRE_INSNS_FLAGS2(ctx, ISA300); > + > + EA = do_ea_calc(ctx, a->ra, tcg_constant_tl(0)); > + src = cpu_gpr[a->rt]; > + discard = tcg_temp_new(); > + > + memop |= MO_ALIGN; > + switch (a->rb) { > + case 0: /* add and Store */ > + tcg_gen_atomic_add_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > + break; > + case 1: /* xor and Store */ > + tcg_gen_atomic_xor_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > + break; > + case 2: /* Or and Store */ > + tcg_gen_atomic_or_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > + break; > + case 3: /* 'and' and Store */ > + tcg_gen_atomic_and_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > + break; > + case 4: /* Store max unsigned */ > + tcg_gen_atomic_umax_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > + break; > + case 5: /* Store max signed */ > + tcg_gen_atomic_smax_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > + break; > + case 6: /* Store min unsigned */ > + tcg_gen_atomic_umin_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > + break; > + case 7: /* Store min signed */ > + tcg_gen_atomic_smin_fetch_tl(discard, EA, src, ctx->mem_idx, memop); > + break; > + case 24: /* Store twin */ > + if (tb_cflags(ctx->base.tb) & CF_PARALLEL) { > + /* Restart with exclusive lock. */ > + gen_helper_exit_atomic(tcg_env); > + ctx->base.is_jmp = DISAS_NORETURN; > + } else { > + TCGv t = tcg_temp_new(); > + TCGv t2 = tcg_temp_new(); > + TCGv s = tcg_temp_new(); > + TCGv s2 = tcg_temp_new(); > + TCGv ea_plus_s = tcg_temp_new(); > + > + tcg_gen_qemu_ld_tl(t, EA, ctx->mem_idx, memop); > + tcg_gen_addi_tl(ea_plus_s, EA, memop_size(memop)); > + tcg_gen_qemu_ld_tl(t2, ea_plus_s, ctx->mem_idx, memop); > + tcg_gen_movcond_tl(TCG_COND_EQ, s, t, t2, src, t); > + tcg_gen_movcond_tl(TCG_COND_EQ, s2, t, t2, src, t2); > + tcg_gen_qemu_st_tl(s, EA, ctx->mem_idx, memop); > + tcg_gen_qemu_st_tl(s2, ea_plus_s, ctx->mem_idx, memop); > + } > + break; > + default: > + /* invoke data storage error handler */ > + gen_exception_err(ctx, POWERPC_EXCP_DSI, POWERPC_EXCP_INVAL); > + } > + return true; > +} > + > +TRANS(LWAT, do_ld_atomic, DEF_MEMOP(MO_UL)) > +TRANS(STWAT, do_st_atomic, DEF_MEMOP(MO_UL)) > + > +static bool trans_LDAT(DisasContext *ctx, arg_LDAT *a) > +{ > + REQUIRE_64BIT(ctx); > +#if defined(TARGET_PPC64) > + return do_ld_atomic(ctx, a, DEF_MEMOP(MO_UQ)); > +#else > + qemu_build_not_reached(); > +#endif > + return true; > +} > + > +static bool trans_STDAT(DisasContext *ctx, arg_STDAT *a) > +{ > + REQUIRE_64BIT(ctx); > +#if defined(TARGET_PPC64) > + return do_st_atomic(ctx, a, DEF_MEMOP(MO_UQ)); > +#else > + qemu_build_not_reached(); > +#endif > + return true; > +} > -- > 2.55.0 >
