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authorRichard Henderson <rth@twiddle.net>2016-04-05 18:00:33 -0700
committerRichard Henderson <rth@twiddle.net>2017-02-14 08:15:00 +1100
commita01deb36a685365b4a3117112da3cc4f0f79e955 (patch)
tree5b5c12ab0b7d9437f55f4efb452d51f66f6f6337 /target
parent24c328521b19aff2559118809ddf0522d6dfaaea (diff)
target/openrisc: Tidy handling of delayed branches
Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'target')
-rw-r--r--target/openrisc/cpu.h12
-rw-r--r--target/openrisc/gdbstub.c2
-rw-r--r--target/openrisc/interrupt.c4
-rw-r--r--target/openrisc/sys_helper.c2
-rw-r--r--target/openrisc/translate.c40
5 files changed, 25 insertions, 35 deletions
diff --git a/target/openrisc/cpu.h b/target/openrisc/cpu.h
index 82946369dc..50a36ba8ef 100644
--- a/target/openrisc/cpu.h
+++ b/target/openrisc/cpu.h
@@ -83,9 +83,6 @@ enum {
/* Version Register */
#define SPR_VR 0xFFFF003F
-/* Internal flags, delay slot flag */
-#define D_FLAG 1
-
/* Interrupt */
#define NR_IRQS 32
@@ -298,8 +295,7 @@ typedef struct CPUOpenRISCState {
target_ulong lock_addr;
target_ulong lock_value;
- uint32_t flags; /* cpu_flags, we only use it for exception
- in solt so far. */
+ uint32_t dflag; /* In delay slot (boolean) */
/* Fields up to this point are cleared by a CPU reset */
struct {} end_reset_fields;
@@ -392,14 +388,16 @@ int cpu_openrisc_get_phys_data(OpenRISCCPU *cpu,
#include "exec/cpu-all.h"
+#define TB_FLAGS_DFLAG 1
+#define TB_FLAGS_OVE SR_OVE
+
static inline void cpu_get_tb_cpu_state(CPUOpenRISCState *env,
target_ulong *pc,
target_ulong *cs_base, uint32_t *flags)
{
*pc = env->pc;
*cs_base = 0;
- /* D_FLAG -- branch instruction exception, OVE overflow trap enable. */
- *flags = (env->flags & D_FLAG) | (env->sr & SR_OVE);
+ *flags = env->dflag | (env->sr & SR_OVE);
}
static inline int cpu_mmu_index(CPUOpenRISCState *env, bool ifetch)
diff --git a/target/openrisc/gdbstub.c b/target/openrisc/gdbstub.c
index 2a4821fe9b..b18c7e9f05 100644
--- a/target/openrisc/gdbstub.c
+++ b/target/openrisc/gdbstub.c
@@ -73,7 +73,7 @@ int openrisc_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
also clear delayed branch status. */
if (env->pc != tmp) {
env->pc = tmp;
- env->flags = 0;
+ env->dflag = 0;
}
break;
diff --git a/target/openrisc/interrupt.c b/target/openrisc/interrupt.c
index 042506f014..a2eec6fb32 100644
--- a/target/openrisc/interrupt.c
+++ b/target/openrisc/interrupt.c
@@ -34,8 +34,8 @@ void openrisc_cpu_do_interrupt(CPUState *cs)
CPUOpenRISCState *env = &cpu->env;
env->epcr = env->pc;
- if (env->flags & D_FLAG) {
- env->flags &= ~D_FLAG;
+ if (env->dflag) {
+ env->dflag = 0;
env->sr |= SR_DSX;
env->epcr -= 4;
} else {
diff --git a/target/openrisc/sys_helper.c b/target/openrisc/sys_helper.c
index 0968901426..60c3193656 100644
--- a/target/openrisc/sys_helper.c
+++ b/target/openrisc/sys_helper.c
@@ -45,7 +45,7 @@ void HELPER(mtspr)(CPUOpenRISCState *env,
when "jumping" to the current instruction. */
if (env->pc != rb) {
env->pc = rb;
- env->flags = 0;
+ env->dflag = 0;
cpu_loop_exit(cs);
}
break;
diff --git a/target/openrisc/translate.c b/target/openrisc/translate.c
index 10f0633e91..313dae2a2c 100644
--- a/target/openrisc/translate.c
+++ b/target/openrisc/translate.c
@@ -40,11 +40,11 @@
typedef struct DisasContext {
TranslationBlock *tb;
target_ulong pc;
- uint32_t tb_flags, synced_flags, flags;
uint32_t is_jmp;
uint32_t mem_idx;
- int singlestep_enabled;
+ uint32_t tb_flags;
uint32_t delayed_branch;
+ bool singlestep_enabled;
} DisasContext;
static TCGv_env cpu_env;
@@ -60,7 +60,7 @@ static TCGv cpu_lock_addr;
static TCGv cpu_lock_value;
static TCGv_i32 fpcsr;
static TCGv_i64 cpu_mac; /* MACHI:MACLO */
-static TCGv_i32 env_flags;
+static TCGv_i32 cpu_dflag;
#include "exec/gen-icount.h"
void openrisc_translate_init(void)
@@ -77,9 +77,9 @@ void openrisc_translate_init(void)
tcg_ctx.tcg_env = cpu_env;
cpu_sr = tcg_global_mem_new(cpu_env,
offsetof(CPUOpenRISCState, sr), "sr");
- env_flags = tcg_global_mem_new_i32(cpu_env,
- offsetof(CPUOpenRISCState, flags),
- "flags");
+ cpu_dflag = tcg_global_mem_new_i32(cpu_env,
+ offsetof(CPUOpenRISCState, dflag),
+ "dflag");
cpu_pc = tcg_global_mem_new(cpu_env,
offsetof(CPUOpenRISCState, pc), "pc");
cpu_ppc = tcg_global_mem_new(cpu_env,
@@ -111,15 +111,6 @@ void openrisc_translate_init(void)
}
}
-static inline void gen_sync_flags(DisasContext *dc)
-{
- /* Sync the tb dependent flag between translate and runtime. */
- if ((dc->tb_flags ^ dc->synced_flags) & D_FLAG) {
- tcg_gen_movi_tl(env_flags, dc->tb_flags & D_FLAG);
- dc->synced_flags = dc->tb_flags;
- }
-}
-
static void gen_exception(DisasContext *dc, unsigned int excp)
{
TCGv_i32 tmp = tcg_const_i32(excp);
@@ -230,8 +221,6 @@ static void gen_jump(DisasContext *dc, int32_t n26, uint32_t reg, uint32_t op0)
}
dc->delayed_branch = 2;
- dc->tb_flags |= D_FLAG;
- gen_sync_flags(dc);
}
static void gen_ove_cy(DisasContext *dc)
@@ -1512,10 +1501,9 @@ void gen_intermediate_code(CPUOpenRISCState *env, struct TranslationBlock *tb)
dc->is_jmp = DISAS_NEXT;
dc->pc = pc_start;
- dc->flags = cpu->env.cpucfgr;
dc->mem_idx = cpu_mmu_index(&cpu->env, false);
- dc->synced_flags = dc->tb_flags = tb->flags;
- dc->delayed_branch = (dc->tb_flags & D_FLAG) != 0;
+ dc->tb_flags = tb->flags;
+ dc->delayed_branch = (dc->tb_flags & TB_FLAGS_DFLAG) != 0;
dc->singlestep_enabled = cs->singlestep_enabled;
next_page_start = (pc_start & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE;
@@ -1539,7 +1527,8 @@ void gen_intermediate_code(CPUOpenRISCState *env, struct TranslationBlock *tb)
gen_tb_start(tb);
do {
- tcg_gen_insn_start(dc->pc, num_insns != 0);
+ tcg_gen_insn_start(dc->pc, (dc->delayed_branch ? 1 : 0)
+ | (num_insns ? 2 : 0));
num_insns++;
if (unlikely(cpu_breakpoint_test(cs, dc->pc, BP_ANY))) {
@@ -1564,8 +1553,6 @@ void gen_intermediate_code(CPUOpenRISCState *env, struct TranslationBlock *tb)
if (dc->delayed_branch) {
dc->delayed_branch--;
if (!dc->delayed_branch) {
- dc->tb_flags &= ~D_FLAG;
- gen_sync_flags(dc);
tcg_gen_mov_tl(cpu_pc, jmp_pc);
tcg_gen_discard_tl(jmp_pc);
dc->is_jmp = DISAS_UPDATE;
@@ -1583,6 +1570,10 @@ void gen_intermediate_code(CPUOpenRISCState *env, struct TranslationBlock *tb)
gen_io_end();
}
+ if ((dc->tb_flags & TB_FLAGS_DFLAG ? 1 : 0) != (dc->delayed_branch != 0)) {
+ tcg_gen_movi_i32(cpu_dflag, dc->delayed_branch != 0);
+ }
+
tcg_gen_movi_tl(cpu_ppc, dc->pc - 4);
if (dc->is_jmp == DISAS_NEXT) {
dc->is_jmp = DISAS_UPDATE;
@@ -1641,7 +1632,8 @@ void restore_state_to_opc(CPUOpenRISCState *env, TranslationBlock *tb,
target_ulong *data)
{
env->pc = data[0];
- if (data[1]) {
+ env->dflag = data[1] & 1;
+ if (data[1] & 2) {
env->ppc = env->pc - 4;
}
}