From a371684da99de63c6700f74c09e9250263d227b7 Mon Sep 17 00:00:00 2001
From: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Date: Tue, 19 Mar 2019 05:36:46 -0400
Subject: [PATCH] target/riscv: Remove gen_system()

with all 16 bit insns moved to decodetree no path is falling back to
gen_system(), so we can remove it.

Backports commit 8f7bc273868939f0821e07fb23792db63d45bffb from qemu
---
 qemu/target/riscv/translate.c | 36 -----------------------------------
 1 file changed, 36 deletions(-)

diff --git a/qemu/target/riscv/translate.c b/qemu/target/riscv/translate.c
index 95c6e74a..c62a87d0 100644
--- a/qemu/target/riscv/translate.c
+++ b/qemu/target/riscv/translate.c
@@ -492,35 +492,6 @@ static void gen_set_rm(DisasContext *ctx, int rm)
     tcg_temp_free_i32(tcg_ctx, t0);
 }
 
-static void gen_system(DisasContext *ctx, uint32_t opc, int rd, int rs1,
-                       int csr)
-{
-    TCGContext *tcg_ctx = ctx->uc->tcg_ctx;
-
-    tcg_gen_movi_tl(tcg_ctx, tcg_ctx->cpu_pc_risc, ctx->base.pc_next);
-
-    switch (opc) {
-    case OPC_RISC_ECALL:
-        switch (csr) {
-        case 0x0: /* ECALL */
-            /* always generates U-level ECALL, fixed in do_interrupt handler */
-            generate_exception(ctx, RISCV_EXCP_U_ECALL);
-            tcg_gen_exit_tb(tcg_ctx, NULL, 0); /* no chaining */
-            ctx->base.is_jmp = DISAS_NORETURN;
-            break;
-        case 0x1: /* EBREAK */
-            generate_exception(ctx, RISCV_EXCP_BREAKPOINT);
-            tcg_gen_exit_tb(tcg_ctx, NULL, 0); /* no chaining */
-            ctx->base.is_jmp = DISAS_NORETURN;
-            break;
-        default:
-            gen_exception_illegal(ctx);
-            break;
-        }
-        break;
-    }
-}
-
 static void decode_RV32_64C0(DisasContext *ctx)
 {
     uint8_t funct3 = extract32(ctx->opcode, 13, 3);
@@ -704,7 +675,6 @@ bool decode_insn16(DisasContext *ctx, uint16_t insn);
 
 static void decode_RV32_64G(DisasContext *ctx)
 {
-    int rs1, rd;
     uint32_t op;
 
     /* We do not do misaligned address check here: the address should never be
@@ -713,14 +683,8 @@ static void decode_RV32_64G(DisasContext *ctx)
      * perform the misaligned instruction fetch */
 
     op = MASK_OP_MAJOR(ctx->opcode);
-    rs1 = GET_RS1(ctx->opcode);
-    rd = GET_RD(ctx->opcode);
 
     switch (op) {
-    case OPC_RISC_SYSTEM:
-        gen_system(ctx, MASK_OP_SYSTEM(ctx->opcode), rd, rs1,
-                   (ctx->opcode & 0xFFF00000) >> 20);
-        break;
     default:
         gen_exception_illegal(ctx);
         break;