From 2c1ae7a4088dc1d81feba8696d52ed2f9b8c9dc1 Mon Sep 17 00:00:00 2001
From: Richard Henderson <rth@twiddle.net>
Date: Fri, 16 Feb 2018 00:52:42 -0500
Subject: [PATCH] target-sparc: Remove gen_opc_jump_pc

Since jump_pc[1] is always npc + 4, we can infer after incrementing
that jump_pc[1] == pc + 4. Because of that, we can encode the branch
destination into a single word, and store that in npc.

Backports commit 6c42444f9a53b6af39d46008cb9f650b11e96cb9 from qemu
---
 qemu/target-sparc/translate.c | 17 ++++++++++-------
 qemu/tcg/tcg.h                |  1 -
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/qemu/target-sparc/translate.c b/qemu/target-sparc/translate.c
index 3bab22ac..511690e5 100644
--- a/qemu/target-sparc/translate.c
+++ b/qemu/target-sparc/translate.c
@@ -5440,6 +5440,10 @@ static inline void gen_intermediate_code_internal(SPARCCPU *cpu,
                     tcg_ctx->gen_opc_instr_start[lj++] = 0;
                 tcg_ctx->gen_opc_pc[lj] = dc->pc;
                 tcg_ctx->gen_opc_npc[lj] = dc->npc;
+                if (dc->npc & JUMP_PC) {
+                    assert(dc->jump_pc[1] == dc->pc + 4);
+                    tcg_ctx->gen_opc_npc[lj] = dc->jump_pc[0] | JUMP_PC;
+                }
                 tcg_ctx->gen_opc_instr_start[lj] = 1;
                 tcg_ctx->gen_opc_icount[lj] = num_insns;
             }
@@ -5515,8 +5519,6 @@ done_generating:
 #if 0
         log_page_dump();
 #endif
-        tcg_ctx->gen_opc_jump_pc[0] = dc->jump_pc[0];
-        tcg_ctx->gen_opc_jump_pc[1] = dc->jump_pc[1];
     } else {
         tb->size = last_pc + 4 - pc_start;
         tb->icount = num_insns;
@@ -5699,16 +5701,17 @@ void gen_intermediate_code_init(CPUSPARCState *env)
 void restore_state_to_opc(CPUSPARCState *env, TranslationBlock *tb, int pc_pos)
 {
     TCGContext *tcg_ctx = env->uc->tcg_ctx;
-    target_ulong npc;
+    target_ulong pc, npc;
+    env->pc = pc = tcg_ctx->gen_opc_pc[pc_pos];
     npc = tcg_ctx->gen_opc_npc[pc_pos];
-    if (npc == 1) {
+    if (npc == DYNAMIC_PC) {
         /* dynamic NPC: already stored */
-    } else if (npc == 2) {
+    } else if (npc & JUMP_PC) {
         /* jump PC: use 'cond' and the jump targets of the translation */
         if (env->cond) {
-            env->npc = tcg_ctx->gen_opc_jump_pc[0];
+            env->npc = npc & ~3;
         } else {
-            env->npc = tcg_ctx->gen_opc_jump_pc[1];
+            env->npc = pc + 4;
         }
     } else {
         env->npc = npc;
diff --git a/qemu/tcg/tcg.h b/qemu/tcg/tcg.h
index 9e995793..a57ca85c 100644
--- a/qemu/tcg/tcg.h
+++ b/qemu/tcg/tcg.h
@@ -804,7 +804,6 @@ struct TCGContext {
     TCGv_i64 cpu_fpr[32];   // TARGET_DPREGS = 32 for Sparc64, 16 for Sparc
 
     target_ulong gen_opc_npc[OPC_BUF_SIZE];
-    target_ulong gen_opc_jump_pc[2];
 
     // void *cpu_cc_src, *cpu_cc_src2, *cpu_cc_dst;
     void *cpu_fsr, *sparc_cpu_pc, *cpu_npc, *cpu_gregs[8];