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From: Yongbok Kim <yongbok.kim@mips.com>
To: qemu-devel@nongnu.org
Cc: aurelien@aurel32.net, Aleksandar.Markovic@mips.com,
	James.Hogan@mips.com, Paul.Burton@mips.com,
	Matthew.Fortune@mips.com, Stefan.Markovic@mips.com
Subject: [Qemu-devel] [PATCH 18/35] target/mips: Add nanoMIPS branch instructions
Date: Wed, 20 Jun 2018 13:06:03 +0100	[thread overview]
Message-ID: <20180620120620.12806-19-yongbok.kim@mips.com> (raw)
In-Reply-To: <20180620120620.12806-1-yongbok.kim@mips.com>

Add nanoMIPS branch instructions

Signed-off-by: Yongbok Kim <yongbok.kim@mips.com>
---
 target/mips/translate.c | 277 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 277 insertions(+)

diff --git a/target/mips/translate.c b/target/mips/translate.c
index 08765a7..948d3d5 100644
--- a/target/mips/translate.c
+++ b/target/mips/translate.c
@@ -16597,6 +16597,168 @@ static void gen_pool32axf_nanomips_insn(CPUMIPSState *env, DisasContext *ctx)
     }
 }
 
+/* Immediate Value Compact Branches */
+static void gen_compute_imm_branch(DisasContext *ctx, uint32_t opc,
+                                   int rt, int32_t imm, int32_t offset)
+{
+    int bcond_compute = 0;
+    TCGv t0 = tcg_temp_new();
+    TCGv t1 = tcg_temp_new();
+
+    if (ctx->hflags & MIPS_HFLAG_BMASK) {
+#ifdef MIPS_DEBUG_DISAS
+        LOG_DISAS("Branch in delay / forbidden slot at PC 0x" TARGET_FMT_lx
+                  "\n", ctx->base.pc_next);
+#endif
+        generate_exception_end(ctx, EXCP_RI);
+        goto out;
+    }
+
+    gen_load_gpr(t0, rt);
+    tcg_gen_movi_tl(t1, imm);
+    ctx->btarget = addr_add(ctx, ctx->base.pc_next + 4, offset);
+
+    /* Load needed operands and calculate btarget */
+    switch (opc) {
+    case NM_BEQIC:
+        if (rt == 0 && imm == 0) {
+            /* Unconditional branch */
+        } else if (rt == 0 && imm != 0) {
+            /* Treat as NOP */
+            goto out;
+        } else {
+            bcond_compute = 1;
+        }
+        break;
+    case NM_BBEQZC:
+    case NM_BBNEZC:
+        if (imm >= 32 && !(ctx->hflags & MIPS_HFLAG_64)) {
+            generate_exception_end(ctx, EXCP_RI);
+            goto out;
+        } else if (rt == 0 && opc == NM_BBEQZC) {
+            /* Unconditional branch */
+        } else if (rt == 0 && opc == NM_BBNEZC) {
+            /* Treat as NOP */
+            goto out;
+        } else {
+            tcg_gen_shri_tl(t0, t0, imm);
+            tcg_gen_andi_tl(t0, t0, 1);
+            tcg_gen_movi_tl(t1, 0);
+            bcond_compute = 1;
+        }
+        break;
+    case NM_BNEIC:
+        if (rt == 0 && imm == 0) {
+            /* Treat as NOP */
+            goto out;
+        } else if (rt == 0 && imm != 0) {
+            /* Unconditional branch */
+        } else {
+            bcond_compute = 1;
+        }
+        break;
+    case NM_BGEIC:
+        if (rt == 0 && imm == 0) {
+            /* Unconditional branch */
+        } else  {
+            bcond_compute = 1;
+        }
+        break;
+    case NM_BLTIC:
+        bcond_compute = 1;
+        break;
+    case NM_BGEIUC:
+        if (rt == 0 && imm == 0) {
+            /* Unconditional branch */
+        } else  {
+            bcond_compute = 1;
+        }
+        break;
+    case NM_BLTIUC:
+        bcond_compute = 1;
+        break;
+    default:
+        MIPS_INVAL("Immediate Value Compact branch");
+        generate_exception_end(ctx, EXCP_RI);
+        goto out;
+    }
+
+    if (bcond_compute == 0) {
+        /* Uncoditional compact branch */
+        ctx->hflags |= MIPS_HFLAG_B;
+        /* Generating branch here as compact branches don't have delay slot */
+        gen_branch(ctx, 4);
+    } else {
+        /* Conditional compact branch */
+        TCGLabel *fs = gen_new_label();
+        save_cpu_state(ctx, 0);
+
+        switch (opc) {
+        case NM_BEQIC:
+            tcg_gen_brcond_tl(tcg_invert_cond(TCG_COND_EQ), t0, t1, fs);
+            break;
+        case NM_BBEQZC:
+            tcg_gen_brcond_tl(tcg_invert_cond(TCG_COND_EQ), t0, t1, fs);
+            break;
+        case NM_BNEIC:
+            tcg_gen_brcond_tl(tcg_invert_cond(TCG_COND_NE), t0, t1, fs);
+            break;
+        case NM_BBNEZC:
+            tcg_gen_brcond_tl(tcg_invert_cond(TCG_COND_NE), t0, t1, fs);
+            break;
+        case NM_BGEIC:
+            tcg_gen_brcond_tl(tcg_invert_cond(TCG_COND_GE), t0, t1, fs);
+            break;
+        case NM_BLTIC:
+            tcg_gen_brcond_tl(tcg_invert_cond(TCG_COND_LT), t0, t1, fs);
+            break;
+        case NM_BGEIUC:
+            tcg_gen_brcond_tl(tcg_invert_cond(TCG_COND_GEU), t0, t1, fs);
+            break;
+        case NM_BLTIUC:
+            tcg_gen_brcond_tl(tcg_invert_cond(TCG_COND_LTU), t0, t1, fs);
+            break;
+        }
+
+        /* Generating branch here as compact branches don't have delay slot */
+        gen_goto_tb(ctx, 1, ctx->btarget);
+        gen_set_label(fs);
+
+        ctx->hflags |= MIPS_HFLAG_FBNSLOT;
+    }
+
+out:
+    tcg_temp_free(t0);
+    tcg_temp_free(t1);
+}
+
+/* P.BALRSC type nanoMIPS R6 branches: BALRSC and BRSC */
+static void gen_compute_nanomips_pbalrsc_branch(DisasContext *ctx, int rs,
+                                                int rt)
+{
+    TCGv t0 = tcg_temp_new();
+    TCGv t1 = tcg_temp_new();
+
+    /* load rs */
+    gen_load_gpr(t0, rs);
+
+    /* link */
+    if (rt != 0) {
+        tcg_gen_movi_tl(cpu_gpr[rt], ctx->base.pc_next + 4);
+    }
+
+    /* calculate btarget */
+    tcg_gen_shli_tl(t0, t0, 1);
+    tcg_gen_movi_tl(t1, ctx->base.pc_next + 4);
+    gen_op_addr_add(ctx, btarget, t1, t0);
+
+    ctx->hflags |= MIPS_HFLAG_BR;
+    /* Generating branch here as compact branches don't have delay slot */
+    gen_branch(ctx, 4);
+
+    tcg_temp_free(t0);
+    tcg_temp_free(t1);
+}
 
 static void gen_p_lsx(DisasContext *ctx, int rd, int rs, int rt)
 {
@@ -17656,16 +17818,131 @@ static int decode_nanomips_32_48_opc(CPUMIPSState *env, DisasContext *ctx)
     }
         break;
     case NM_MOVE_BALC:
+    {
+        TCGv t0 = tcg_temp_new();
+        int32_t s = sextract32(ctx->opcode, 0, 1) << 21 |
+                    extract32(ctx->opcode, 1, 20) << 1;
+        rd = ((ctx->opcode >> 24) & 1) == 0 ? 4 : 5;
+        rt = mmreg4z_nanomips(extract32(ctx->opcode, 25, 1) << 3 |
+                        extract32(ctx->opcode, 21, 3));
+        gen_load_gpr(t0, rt);
+        tcg_gen_mov_tl(cpu_gpr[rd], t0);
+        gen_compute_branch(ctx, OPC_BGEZAL, 4, 0, 0, s, 0);
+        tcg_temp_free(t0);
+    }
         break;
     case NM_P_BAL:
+        {
+            int32_t s = sextract32(ctx->opcode, 0, 1) << 25 |
+                        extract32(ctx->opcode, 1, 24) << 1;
+
+            if (((ctx->opcode >> 25) & 1) == 0) {
+                /* BC */
+                gen_compute_branch(ctx, OPC_BEQ, 4, 0, 0, s, 0);
+            } else {
+                /* BALC */
+                gen_compute_branch(ctx, OPC_BGEZAL, 4, 0, 0, s, 0);
+            }
+        }
         break;
     case NM_P_J:
+        switch ((ctx->opcode >> 12) & 0x0f) {
+        case NM_JALRC:
+        case NM_JALRC_HB:
+            gen_compute_branch(ctx, OPC_JALR, 4, rs, rt, 0, 0);
+            break;
+        case NM_P_BALRSC:
+            gen_compute_nanomips_pbalrsc_branch(ctx, rs, rt);
+            break;
+        default:
+            generate_exception_end(ctx, EXCP_RI);
+            break;
+        }
         break;
     case NM_P_BR1:
+    {
+        int32_t s = sextract32(ctx->opcode, 0, 1) << 14 |
+                    extract32(ctx->opcode, 1, 13) << 1;
+        switch ((ctx->opcode >> 14) & 0x03) {
+        case NM_BEQC:
+            gen_compute_branch(ctx, OPC_BEQ, 4, rs, rt, s, 0);
+            break;
+        case NM_P_BR3A:
+        {
+            int32_t s = sextract32(ctx->opcode, 0, 1) << 14 |
+                        extract32(ctx->opcode, 1, 13) << 1;
+            check_cp1_enabled(ctx);
+            switch ((ctx->opcode >> 16) & 0x1f) {
+            case NM_BC1EQZC:
+                gen_compute_branch1_r6(ctx, OPC_BC1EQZ, rt, s, 0);
+                break;
+            case NM_BC1NEZC:
+                gen_compute_branch1_r6(ctx, OPC_BC1NEZ, rt, s, 0);
+                break;
+            default:
+                generate_exception_end(ctx, EXCP_RI);
+                break;
+            }
+        }
+            break;
+        case NM_BGEC:
+            if (rs == rt) {
+                gen_compute_compact_branch(ctx, OPC_BC, rs, rt, s);
+            } else {
+                gen_compute_compact_branch(ctx, OPC_BGEC, rs, rt, s);
+            }
+            break;
+        case NM_BGEUC:
+            if (rs == rt || rt == 0) {
+                gen_compute_compact_branch(ctx, OPC_BC, 0, 0, s);
+            } else if (rs == 0) {
+                gen_compute_compact_branch(ctx, OPC_BEQZC, rt, 0, s);
+            } else {
+                gen_compute_compact_branch(ctx, OPC_BGEUC, rs, rt, s);
+            }
+            break;
+        }
+    }
         break;
     case NM_P_BR2:
+    {
+        int32_t s = sextract32(ctx->opcode, 0, 1) << 14 |
+                    extract32(ctx->opcode, 1, 13) << 1;
+        switch ((ctx->opcode >> 14) & 0x03) {
+        case NM_BNEC:
+            gen_compute_branch(ctx, OPC_BNE, 4, rs, rt, s, 0);
+            break;
+        case NM_BLTC:
+            if (rs != 0 && rt != 0 && rs == rt) {
+                /* NOP */
+                ctx->hflags |= MIPS_HFLAG_FBNSLOT;
+            } else {
+                gen_compute_compact_branch(ctx, OPC_BLTC, rs, rt, s);
+            }
+            break;
+        case NM_BLTUC:
+            if (rs == 0 || rs == rt) {
+                /* NOP */
+                ctx->hflags |= MIPS_HFLAG_FBNSLOT;
+            } else {
+                gen_compute_compact_branch(ctx, OPC_BLTUC, rs, rt, s);
+            }
+            break;
+        default:
+            generate_exception_end(ctx, EXCP_RI);
+            break;
+        }
+    }
         break;
     case NM_P_BRI:
+    {
+        int32_t s = sextract32(ctx->opcode, 0, 1) << 11 |
+                    extract32(ctx->opcode, 1, 10) << 1;
+        uint32_t u = extract32(ctx->opcode, 11, 7);
+
+        gen_compute_imm_branch(ctx, extract32(ctx->opcode, 18, 3),
+                               rt, u, s);
+    }
         break;
     default:
         generate_exception_end(ctx, EXCP_RI);
-- 
1.9.1

  parent reply	other threads:[~2018-06-20 12:11 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-20 12:05 [Qemu-devel] [PATCH 00/35] nanoMIPS Yongbok Kim
2018-06-20 12:05 ` [Qemu-devel] [PATCH 01/35] target/mips: Raise a RI when given fs is n/a from CTC1 Yongbok Kim
2018-06-22 13:45   ` Aleksandar Markovic
2018-06-20 12:05 ` [Qemu-devel] [PATCH 02/35] target/mips: Fix microMIPS on reset Yongbok Kim
2018-06-22 13:45   ` Aleksandar Markovic
2018-06-20 12:05 ` [Qemu-devel] [PATCH 03/35] target/mips: Add nanoMIPS OPCODE table Yongbok Kim
2018-06-21 23:15   ` Richard Henderson
2018-06-20 12:05 ` [Qemu-devel] [PATCH 04/35] target/mips: Add decode_nanomips_opc() Yongbok Kim
2018-06-21 23:39   ` Richard Henderson
2018-06-20 12:05 ` [Qemu-devel] [PATCH 05/35] target/mips: Add nanoMIPS 16bit ld/st instructions Yongbok Kim
2018-06-21 23:48   ` Richard Henderson
2018-06-20 12:05 ` [Qemu-devel] [PATCH 06/35] target/mips: Add nanoMIPS pool16c instructions Yongbok Kim
2018-06-22  3:40   ` Richard Henderson
2018-06-20 12:05 ` [Qemu-devel] [PATCH 07/35] target/mips: Add nanoMIPS save and restore Yongbok Kim
2018-06-22  5:11   ` Richard Henderson
2018-06-20 12:05 ` [Qemu-devel] [PATCH 08/35] target/mips: Add nanoMIPS 32bit instructions Yongbok Kim
2018-06-24 23:32   ` Richard Henderson
2018-06-20 12:05 ` [Qemu-devel] [PATCH 09/35] target/mips: Add nanoMIPS 48bit instructions Yongbok Kim
2018-06-24 23:49   ` Richard Henderson
2018-06-20 12:05 ` [Qemu-devel] [PATCH 10/35] target/mips: Add nanoMIPS pool32f instructions Yongbok Kim
2018-06-20 12:05 ` [Qemu-devel] [PATCH 11/35] target/mips: Add nanoMIPS pool32a0 instructions Yongbok Kim
2018-06-24 23:59   ` Richard Henderson
2018-06-20 12:05 ` [Qemu-devel] [PATCH 12/35] target/mips: Add nanoMIPS pool32axf instructions Yongbok Kim
2018-06-20 12:05 ` [Qemu-devel] [PATCH 13/35] target/mips: Update gen_flt_ldst() Yongbok Kim
2018-06-22  4:13   ` Philippe Mathieu-Daudé
2018-06-22 13:46   ` Aleksandar Markovic
2018-06-20 12:05 ` [Qemu-devel] [PATCH 14/35] target/mips: Add nanoMIPS p_lsx instructions Yongbok Kim
2018-06-25  0:07   ` Richard Henderson
2018-06-20 12:06 ` [Qemu-devel] [PATCH 15/35] target/mips: Implement nanoMIPS EXTW instruction Yongbok Kim
2018-06-20 12:06 ` [Qemu-devel] [PATCH 16/35] target/mips: Add has_isa_mode Yongbok Kim
2018-06-20 12:06 ` [Qemu-devel] [PATCH 17/35] target/mips: Add nanoMIPS load store instructions Yongbok Kim
2018-06-20 12:06 ` Yongbok Kim [this message]
2018-06-25  0:23   ` [Qemu-devel] [PATCH 18/35] target/mips: Add nanoMIPS branch instructions Richard Henderson
2018-06-20 12:06 ` [Qemu-devel] [PATCH 19/35] target/mips: Implement nanoMIPS LLWP/SCWP pair Yongbok Kim
2018-06-25  0:27   ` Richard Henderson
2018-06-20 12:06 ` [Qemu-devel] [PATCH 20/35] target/mips: Fix not to update BadVAddr in Debug Mode Yongbok Kim
2018-06-22  4:15   ` Philippe Mathieu-Daudé
2018-06-20 12:06 ` [Qemu-devel] [PATCH 21/35] target/mips: Add nanoMIPS rotx instruction Yongbok Kim
2018-06-25  0:30   ` Richard Henderson
2018-06-20 12:06 ` [Qemu-devel] [PATCH 22/35] target/mips: Fix data type for offset Yongbok Kim
2018-06-22  4:16   ` Philippe Mathieu-Daudé
2018-06-22 13:47   ` Aleksandar Markovic
2018-06-20 12:06 ` [Qemu-devel] [PATCH 23/35] target/mips: Update BadInstr{P} regs on nanoMIPS Yongbok Kim
2018-06-20 12:06 ` [Qemu-devel] [PATCH 24/35] target/mips: Add nanoMIPS CP0_BadInstrX register Yongbok Kim
2018-06-20 12:06 ` [Qemu-devel] [PATCH 25/35] target/mips: Config3.ISAOnExc is read only in nanoMIPS Yongbok Kim
2018-06-20 12:06 ` [Qemu-devel] [PATCH 26/35] target/mips: Fix nanoMIPS exception_resume_pc Yongbok Kim
2018-06-20 12:06 ` [Qemu-devel] [PATCH 27/35] target/mips: Fix nanoMIPS set_hflags_for_handler Yongbok Kim
2018-06-20 12:06 ` [Qemu-devel] [PATCH 28/35] target/mips: Fix nanoMIPS set_pc Yongbok Kim
2018-06-20 12:06 ` [Qemu-devel] [PATCH 29/35] target/mips: Fix ERET/ERETNC can cause ADEL exception Yongbok Kim
2018-06-22  4:31   ` Philippe Mathieu-Daudé
2018-06-20 12:06 ` [Qemu-devel] [PATCH 30/35] hw/mips: Add basic nanoMIPS boot code Yongbok Kim
2018-06-20 12:06 ` [Qemu-devel] [PATCH 31/35] mips_malta: Setup GT64120 BARs in nanoMIPS bootloader Yongbok Kim
2018-06-20 12:06 ` [Qemu-devel] [PATCH 32/35] hw/mips: Fix semihosting argument passing for nanoMIPS bare metal Yongbok Kim
2018-06-20 12:06 ` [Qemu-devel] [PATCH 33/35] target/mips: Fix gdbstub to read/write 64 bit FP registers Yongbok Kim
2018-06-22 13:47   ` Aleksandar Markovic
2018-06-20 12:06 ` [Qemu-devel] [PATCH 34/35] target/mips: Disable gdbstub nanoMIPS ISA bit Yongbok Kim
2018-06-20 12:06 ` [Qemu-devel] [PATCH 35/35] target/mips: Add I7200 CPU Yongbok Kim
2018-06-22  4:26 ` [Qemu-devel] [PATCH 00/35] nanoMIPS Philippe Mathieu-Daudé
2018-06-22 14:39   ` Aleksandar Markovic
2018-06-22 15:16     ` Philippe Mathieu-Daudé
2018-06-22 15:31       ` Peter Maydell
2018-06-22 14:21 ` Aleksandar Markovic

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