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target/xtensa: move WINDOW_BASE SR update to postprocessing 

Opcodes that modify WINDOW_BASE SR don't have dependency on opcodes that
use windowed registers. If such opcodes are combined in a single
instruction they may not be correctly ordered. Instead of adding said
dependency use temporary register to store changed WINDOW_BASE value and
do actual register window rotation as a postprocessing step.
Not all opcodes that change WINDOW_BASE need this: retw, rfwo and rfwu
are also jump opcodes, so they are guaranteed to be translated last and
thus will not affect other opcodes in the same instruction.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
This commit is contained in:
Max Filippov 2019-01-30 14:56:29 -08:00
parent 45b71a795e
commit 8df3fd3596
4 changed files with 28 additions and 20 deletions
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1
target/xtensa/cpu.h
View File

@ -486,6 +486,7 @@ typedef struct CPUXtensaState {
float64 f64;
} fregs[16];
float_status fp_status;
uint32_t windowbase_next;
#ifndef CONFIG_USER_ONLY
xtensa_tlb_entry itlb[7][MAX_TLB_WAY_SIZE];

3
target/xtensa/helper.h
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@ -3,12 +3,11 @@ DEF_HELPER_3(exception_cause, noreturn, env, i32, i32)
DEF_HELPER_4(exception_cause_vaddr, noreturn, env, i32, i32, i32)
DEF_HELPER_3(debug_exception, noreturn, env, i32, i32)
DEF_HELPER_2(wsr_windowbase, void, env, i32)
DEF_HELPER_1(sync_windowbase, void, env)
DEF_HELPER_4(entry, void, env, i32, i32, i32)
DEF_HELPER_2(test_ill_retw, void, env, i32)
DEF_HELPER_2(test_underflow_retw, void, env, i32)
DEF_HELPER_2(retw, i32, env, i32)
DEF_HELPER_2(rotw, void, env, i32)
DEF_HELPER_3(window_check, noreturn, env, i32, i32)
DEF_HELPER_1(restore_owb, void, env)
DEF_HELPER_2(movsp, void, env, i32)

30
target/xtensa/translate.c
View File

@ -82,6 +82,7 @@ static TCGv_i32 cpu_R[16];
static TCGv_i32 cpu_FR[16];
static TCGv_i32 cpu_SR[256];
static TCGv_i32 cpu_UR[256];
static TCGv_i32 cpu_windowbase_next;
#include "exec/gen-icount.h"
@ -253,6 +254,11 @@ void xtensa_translate_init(void)
uregnames[i].name);
}
}
cpu_windowbase_next =
tcg_global_mem_new_i32(cpu_env,
offsetof(CPUXtensaState, windowbase_next),
"windowbase_next");
}
static inline bool option_enabled(DisasContext *dc, int opt)
@ -557,7 +563,7 @@ static void gen_wsr_acchi(DisasContext *dc, uint32_t sr, TCGv_i32 s)
#ifndef CONFIG_USER_ONLY
static void gen_wsr_windowbase(DisasContext *dc, uint32_t sr, TCGv_i32 v)
{
gen_helper_wsr_windowbase(cpu_env, v);
tcg_gen_mov_i32(cpu_windowbase_next, v);
}
static void gen_wsr_windowstart(DisasContext *dc, uint32_t sr, TCGv_i32 v)
@ -859,6 +865,9 @@ static int gen_postprocess(DisasContext *dc, int slot)
if (op_flags & XTENSA_OP_CHECK_INTERRUPTS) {
gen_check_interrupts(dc);
}
if (op_flags & XTENSA_OP_SYNC_REGISTER_WINDOW) {
gen_helper_sync_windowbase(cpu_env);
}
if (op_flags & XTENSA_OP_EXIT_TB_M1) {
slot = -1;
}
@ -2268,9 +2277,7 @@ static void translate_rfw(DisasContext *dc, const uint32_t arg[],
static void translate_rotw(DisasContext *dc, const uint32_t arg[],
const uint32_t par[])
{
TCGv_i32 tmp = tcg_const_i32(arg[0]);
gen_helper_rotw(cpu_env, tmp);
tcg_temp_free(tmp);
tcg_gen_addi_i32(cpu_windowbase_next, cpu_SR[WINDOW_BASE], arg[0]);
}
static void translate_rsil(DisasContext *dc, const uint32_t arg[],
@ -2972,7 +2979,8 @@ static const XtensaOpcodeOps core_ops[] = {
.translate = translate_entry,
.test_ill = test_ill_entry,
.test_overflow = test_overflow_entry,
.op_flags = XTENSA_OP_EXIT_TB_M1,
.op_flags = XTENSA_OP_EXIT_TB_M1 |
XTENSA_OP_SYNC_REGISTER_WINDOW,
}, {
.name = "esync",
.translate = translate_nop,
@ -3554,7 +3562,9 @@ static const XtensaOpcodeOps core_ops[] = {
}, {
.name = "rotw",
.translate = translate_rotw,
.op_flags = XTENSA_OP_PRIVILEGED | XTENSA_OP_EXIT_TB_M1,
.op_flags = XTENSA_OP_PRIVILEGED |
XTENSA_OP_EXIT_TB_M1 |
XTENSA_OP_SYNC_REGISTER_WINDOW,
}, {
.name = "rsil",
.translate = translate_rsil,
@ -4622,7 +4632,9 @@ static const XtensaOpcodeOps core_ops[] = {
.translate = translate_wsr,
.test_ill = test_ill_wsr,
.par = (const uint32_t[]){WINDOW_BASE},
.op_flags = XTENSA_OP_PRIVILEGED | XTENSA_OP_EXIT_TB_M1,
.op_flags = XTENSA_OP_PRIVILEGED |
XTENSA_OP_EXIT_TB_M1 |
XTENSA_OP_SYNC_REGISTER_WINDOW,
}, {
.name = "wsr.windowstart",
.translate = translate_wsr,
@ -5108,7 +5120,9 @@ static const XtensaOpcodeOps core_ops[] = {
.translate = translate_xsr,
.test_ill = test_ill_xsr,
.par = (const uint32_t[]){WINDOW_BASE},
.op_flags = XTENSA_OP_PRIVILEGED | XTENSA_OP_EXIT_TB_M1,
.op_flags = XTENSA_OP_PRIVILEGED |
XTENSA_OP_EXIT_TB_M1 |
XTENSA_OP_SYNC_REGISTER_WINDOW,
}, {
.name = "xsr.windowstart",
.translate = translate_xsr,

14
target/xtensa/win_helper.c
View File

@ -96,9 +96,9 @@ void xtensa_rotate_window(CPUXtensaState *env, uint32_t delta)
xtensa_rotate_window_abs(env, env->sregs[WINDOW_BASE] + delta);
}
void HELPER(wsr_windowbase)(CPUXtensaState *env, uint32_t v)
void HELPER(sync_windowbase)(CPUXtensaState *env)
{
xtensa_rotate_window_abs(env, v);
xtensa_rotate_window_abs(env, env->windowbase_next);
}
void HELPER(entry)(CPUXtensaState *env, uint32_t pc, uint32_t s, uint32_t imm)
@ -106,9 +106,8 @@ void HELPER(entry)(CPUXtensaState *env, uint32_t pc, uint32_t s, uint32_t imm)
int callinc = (env->sregs[PS] & PS_CALLINC) >> PS_CALLINC_SHIFT;
env->regs[(callinc << 2) | (s & 3)] = env->regs[s] - imm;
xtensa_rotate_window(env, callinc);
env->sregs[WINDOW_START] |=
windowstart_bit(env->sregs[WINDOW_BASE], env);
env->windowbase_next = env->sregs[WINDOW_BASE] + callinc;
env->sregs[WINDOW_START] |= windowstart_bit(env->windowbase_next, env);
}
void HELPER(window_check)(CPUXtensaState *env, uint32_t pc, uint32_t w)
@ -196,11 +195,6 @@ uint32_t HELPER(retw)(CPUXtensaState *env, uint32_t pc)
return ret_pc;
}
void HELPER(rotw)(CPUXtensaState *env, uint32_t imm4)
{
xtensa_rotate_window(env, imm4);
}
void xtensa_restore_owb(CPUXtensaState *env)
{
xtensa_rotate_window_abs(env, (env->sregs[PS] & PS_OWB) >> PS_OWB_SHIFT);