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target-alpha: Emit goto_tb opcodes.

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Use an ExitStatus enumeration instead of magic numbers as the return
value from translate_one.  Emit goto_tb opcodes when ending a TB via
a direct branch.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
Richard Henderson 2010-03-16 15:10:49 -07:00 committed by Aurelien Jarno
parent 593f17e5f2
commit 4af7037462
1 changed files with 197 additions and 151 deletions
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324
target-alpha/translate.c
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@ -43,12 +43,13 @@
typedef struct DisasContext DisasContext;
struct DisasContext {
struct TranslationBlock *tb;
CPUAlphaState *env;
uint64_t pc;
int mem_idx;
#if !defined (CONFIG_USER_ONLY)
int pal_mode;
#endif
CPUAlphaState *env;
uint32_t amask;
/* Current rounding mode for this TB. */
@ -57,6 +58,25 @@ struct DisasContext {
int tb_ftz;
};
/* Return values from translate_one, indicating the state of the TB.
Note that zero indicates that we are not exiting the TB. */
typedef enum {
NO_EXIT,
/* We have emitted one or more goto_tb. No fixup required. */
EXIT_GOTO_TB,
/* We are not using a goto_tb (for whatever reason), but have updated
the PC (for whatever reason), so there's no need to do it again on
exiting the TB. */
EXIT_PC_UPDATED,
/* We are exiting the TB, but have neither emitted a goto_tb, nor
updated the PC for the next instruction to be executed. */
EXIT_PC_STALE
} ExitStatus;
/* global register indexes */
static TCGv_ptr cpu_env;
static TCGv cpu_ir[31];
@ -300,77 +320,126 @@ static inline void gen_store_mem(DisasContext *ctx,
tcg_temp_free(addr);
}
static void gen_bcond_pcload(DisasContext *ctx, int32_t disp, int lab_true)
static int use_goto_tb(DisasContext *ctx, uint64_t dest)
{
/* Check for the dest on the same page as the start of the TB. We
also want to suppress goto_tb in the case of single-steping and IO. */
return (((ctx->tb->pc ^ dest) & TARGET_PAGE_MASK) == 0
&& !ctx->env->singlestep_enabled
&& !(ctx->tb->cflags & CF_LAST_IO));
}
static ExitStatus gen_bdirect(DisasContext *ctx, int ra, int32_t disp)
{
uint64_t dest = ctx->pc + (disp << 2);
if (ra != 31) {
tcg_gen_movi_i64(cpu_ir[ra], ctx->pc);
}
/* Notice branch-to-next; used to initialize RA with the PC. */
if (disp == 0) {
return 0;
} else if (use_goto_tb(ctx, dest)) {
tcg_gen_goto_tb(0);
tcg_gen_movi_i64(cpu_pc, dest);
tcg_gen_exit_tb((long)ctx->tb);
return EXIT_GOTO_TB;
} else {
tcg_gen_movi_i64(cpu_pc, dest);
return EXIT_PC_UPDATED;
}
}
static ExitStatus gen_bcond_internal(DisasContext *ctx, TCGCond cond,
TCGv cmp, int32_t disp)
{
uint64_t dest = ctx->pc + (disp << 2);
int lab_true = gen_new_label();
if (use_goto_tb(ctx, dest)) {
tcg_gen_brcondi_i64(cond, cmp, 0, lab_true);
tcg_gen_goto_tb(0);
tcg_gen_movi_i64(cpu_pc, ctx->pc);
tcg_gen_exit_tb((long)ctx->tb);
gen_set_label(lab_true);
tcg_gen_goto_tb(1);
tcg_gen_movi_i64(cpu_pc, dest);
tcg_gen_exit_tb((long)ctx->tb + 1);
return EXIT_GOTO_TB;
} else {
int lab_over = gen_new_label();
/* ??? Consider using either
movi pc, next
addi tmp, pc, disp
movcond pc, cond, 0, tmp, pc
or
setcond tmp, cond, 0
movi pc, next
neg tmp, tmp
andi tmp, tmp, disp
add pc, pc, tmp
The current diamond subgraph surely isn't efficient. */
tcg_gen_brcondi_i64(cond, cmp, 0, lab_true);
tcg_gen_movi_i64(cpu_pc, ctx->pc);
tcg_gen_br(lab_over);
gen_set_label(lab_true);
tcg_gen_movi_i64(cpu_pc, ctx->pc + (int64_t)(disp << 2));
tcg_gen_movi_i64(cpu_pc, dest);
gen_set_label(lab_over);
return EXIT_PC_UPDATED;
}
}
static void gen_bcond(DisasContext *ctx, TCGCond cond, int ra,
static ExitStatus gen_bcond(DisasContext *ctx, TCGCond cond, int ra,
int32_t disp, int mask)
{
int lab_true = gen_new_label();
TCGv cmp_tmp;
if (likely(ra != 31)) {
if (unlikely(ra == 31)) {
cmp_tmp = tcg_const_i64(0);
} else {
cmp_tmp = tcg_temp_new();
if (mask) {
TCGv tmp = tcg_temp_new();
tcg_gen_andi_i64(tmp, cpu_ir[ra], 1);
tcg_gen_brcondi_i64(cond, tmp, 0, lab_true);
tcg_temp_free(tmp);
tcg_gen_andi_i64(cmp_tmp, cpu_ir[ra], 1);
} else {
tcg_gen_brcondi_i64(cond, cpu_ir[ra], 0, lab_true);
tcg_gen_mov_i64(cmp_tmp, cpu_ir[ra]);
}
} else {
/* Very uncommon case - Do not bother to optimize. */
TCGv tmp = tcg_const_i64(0);
tcg_gen_brcondi_i64(cond, tmp, 0, lab_true);
tcg_temp_free(tmp);
}
gen_bcond_pcload(ctx, disp, lab_true);
}
/* Generate a forward TCG branch to LAB_TRUE if RA cmp 0.0.
This is complicated by the fact that -0.0 compares the same as +0.0. */
return gen_bcond_internal(ctx, cond, cmp_tmp, disp);
}
static void gen_fbcond_internal(TCGCond cond, TCGv src, int lab_true)
/* Fold -0.0 for comparison with COND. */
static void gen_fold_mzero(TCGCond cond, TCGv dest, TCGv src)
{
int lab_false = -1;
uint64_t mzero = 1ull << 63;
TCGv tmp;
switch (cond) {
case TCG_COND_LE:
case TCG_COND_GT:
/* For <= or >, the -0.0 value directly compares the way we want. */
tcg_gen_brcondi_i64(cond, src, 0, lab_true);
tcg_gen_mov_i64(dest, src);
break;
case TCG_COND_EQ:
case TCG_COND_NE:
/* For == or !=, we can simply mask off the sign bit and compare. */
/* ??? Assume that the temporary is reclaimed at the branch. */
tmp = tcg_temp_new();
tcg_gen_andi_i64(tmp, src, mzero - 1);
tcg_gen_brcondi_i64(cond, tmp, 0, lab_true);
tcg_gen_andi_i64(dest, src, mzero - 1);
break;
case TCG_COND_GE:
/* For >=, emit two branches to the destination. */
tcg_gen_brcondi_i64(cond, src, 0, lab_true);
tcg_gen_brcondi_i64(TCG_COND_EQ, src, mzero, lab_true);
break;
case TCG_COND_LT:
/* For <, first filter out -0.0 to what will be the fallthru. */
lab_false = gen_new_label();
tcg_gen_brcondi_i64(TCG_COND_EQ, src, mzero, lab_false);
tcg_gen_brcondi_i64(cond, src, 0, lab_true);
gen_set_label(lab_false);
/* For >= or <, map -0.0 to +0.0 via comparison and mask. */
tcg_gen_setcondi_i64(TCG_COND_NE, dest, src, mzero);
tcg_gen_neg_i64(dest, dest);
tcg_gen_and_i64(dest, dest, src);
break;
default:
@ -378,20 +447,20 @@ static void gen_fbcond_internal(TCGCond cond, TCGv src, int lab_true)
}
}
static void gen_fbcond(DisasContext *ctx, TCGCond cond, int ra, int32_t disp)
static ExitStatus gen_fbcond(DisasContext *ctx, TCGCond cond, int ra,
int32_t disp)
{
int lab_true;
TCGv cmp_tmp;
if (unlikely(ra == 31)) {
/* Very uncommon case, but easier to optimize it to an integer
comparison than continuing with the floating point comparison. */
gen_bcond(ctx, cond, ra, disp, 0);
return;
return gen_bcond(ctx, cond, ra, disp, 0);
}
lab_true = gen_new_label();
gen_fbcond_internal(cond, cpu_fir[ra], lab_true);
gen_bcond_pcload(ctx, disp, lab_true);
cmp_tmp = tcg_temp_new();
gen_fold_mzero(cond, cmp_tmp, cpu_fir[ra]);
return gen_bcond_internal(ctx, cond, cmp_tmp, disp);
}
static void gen_cmov(TCGCond cond, int ra, int rb, int rc,
@ -429,18 +498,23 @@ static void gen_cmov(TCGCond cond, int ra, int rb, int rc,
static void gen_fcmov(TCGCond cond, int ra, int rb, int rc)
{
TCGv va = cpu_fir[ra];
TCGv cmp_tmp;
int l1;
if (unlikely(rc == 31))
if (unlikely(rc == 31)) {
return;
}
cmp_tmp = tcg_temp_new();
if (unlikely(ra == 31)) {
/* ??? Assume that the temporary is reclaimed at the branch. */
va = tcg_const_i64(0);
tcg_gen_movi_i64(cmp_tmp, 0);
} else {
gen_fold_mzero(cond, cmp_tmp, cpu_fir[ra]);
}
l1 = gen_new_label();
gen_fbcond_internal(tcg_invert_cond(cond), va, l1);
tcg_gen_brcondi_i64(tcg_invert_cond(cond), cmp_tmp, 0, l1);
tcg_temp_free(cmp_tmp);
if (rb != 31)
tcg_gen_mov_i64(cpu_fir[rc], cpu_fir[rb]);
@ -1335,14 +1409,14 @@ static void gen_rx(int ra, int set)
tcg_temp_free_i32(tmp);
}
static inline int translate_one(DisasContext *ctx, uint32_t insn)
static ExitStatus translate_one(DisasContext *ctx, uint32_t insn)
{
uint32_t palcode;
int32_t disp21, disp16, disp12;
uint16_t fn11;
uint8_t opc, ra, rb, rc, fpfn, fn7, fn2, islit, real_islit;
uint8_t lit;
int ret;
ExitStatus ret;
/* Decode all instruction fields */
opc = insn >> 26;
@ -1363,10 +1437,10 @@ static inline int translate_one(DisasContext *ctx, uint32_t insn)
fpfn = fn11 & 0x3F;
fn7 = (insn >> 5) & 0x0000007F;
fn2 = (insn >> 5) & 0x00000003;
ret = 0;
LOG_DISAS("opc %02x ra %2d rb %2d rc %2d disp16 %6d\n",
opc, ra, rb, rc, disp16);
ret = NO_EXIT;
switch (opc) {
case 0x00:
/* CALL_PAL */
@ -1384,7 +1458,8 @@ static inline int translate_one(DisasContext *ctx, uint32_t insn)
if (palcode >= 0x80 && palcode < 0xC0) {
/* Unprivileged PAL call */
gen_excp(ctx, EXCP_CALL_PAL + ((palcode & 0x3F) << 6), 0);
ret = 3;
/* PC updated by gen_excp. */
ret = EXIT_PC_UPDATED;
break;
}
#ifndef CONFIG_USER_ONLY
@ -2395,13 +2470,11 @@ static inline int translate_one(DisasContext *ctx, uint32_t insn)
switch ((uint16_t)disp16) {
case 0x0000:
/* TRAPB */
/* No-op. Just exit from the current tb */
ret = 2;
/* No-op. */
break;
case 0x0400:
/* EXCB */
/* No-op. Just exit from the current tb */
ret = 2;
/* No-op. */
break;
case 0x4000:
/* MB */
@ -2465,21 +2538,7 @@ static inline int translate_one(DisasContext *ctx, uint32_t insn)
if (ra != 31)
tcg_gen_movi_i64(cpu_ir[ra], ctx->pc);
/* Those four jumps only differ by the branch prediction hint */
switch (fn2) {
case 0x0:
/* JMP */
break;
case 0x1:
/* JSR */
break;
case 0x2:
/* RET */
break;
case 0x3:
/* JSR_COROUTINE */
break;
}
ret = 1;
ret = EXIT_PC_UPDATED;
break;
case 0x1B:
/* HW_LD (PALcode) */
@ -2770,7 +2829,7 @@ static inline int translate_one(DisasContext *ctx, uint32_t insn)
tcg_temp_free(tmp2);
}
tcg_temp_free(tmp1);
ret = 2;
ret = EXIT_PC_STALE;
}
break;
#endif
@ -2795,7 +2854,7 @@ static inline int translate_one(DisasContext *ctx, uint32_t insn)
gen_helper_hw_ret(tmp);
tcg_temp_free(tmp);
}
ret = 2;
ret = EXIT_PC_UPDATED;
break;
#endif
case 0x1F:
@ -2956,85 +3015,66 @@ static inline int translate_one(DisasContext *ctx, uint32_t insn)
break;
case 0x30:
/* BR */
if (ra != 31)
tcg_gen_movi_i64(cpu_ir[ra], ctx->pc);
tcg_gen_movi_i64(cpu_pc, ctx->pc + (int64_t)(disp21 << 2));
ret = 1;
ret = gen_bdirect(ctx, ra, disp21);
break;
case 0x31: /* FBEQ */
gen_fbcond(ctx, TCG_COND_EQ, ra, disp21);
ret = 1;
ret = gen_fbcond(ctx, TCG_COND_EQ, ra, disp21);
break;
case 0x32: /* FBLT */
gen_fbcond(ctx, TCG_COND_LT, ra, disp21);
ret = 1;
ret = gen_fbcond(ctx, TCG_COND_LT, ra, disp21);
break;
case 0x33: /* FBLE */
gen_fbcond(ctx, TCG_COND_LE, ra, disp21);
ret = 1;
ret = gen_fbcond(ctx, TCG_COND_LE, ra, disp21);
break;
case 0x34:
/* BSR */
if (ra != 31)
tcg_gen_movi_i64(cpu_ir[ra], ctx->pc);
tcg_gen_movi_i64(cpu_pc, ctx->pc + (int64_t)(disp21 << 2));
ret = 1;
ret = gen_bdirect(ctx, ra, disp21);
break;
case 0x35: /* FBNE */
gen_fbcond(ctx, TCG_COND_NE, ra, disp21);
ret = 1;
ret = gen_fbcond(ctx, TCG_COND_NE, ra, disp21);
break;
case 0x36: /* FBGE */
gen_fbcond(ctx, TCG_COND_GE, ra, disp21);
ret = 1;
ret = gen_fbcond(ctx, TCG_COND_GE, ra, disp21);
break;
case 0x37: /* FBGT */
gen_fbcond(ctx, TCG_COND_GT, ra, disp21);
ret = 1;
ret = gen_fbcond(ctx, TCG_COND_GT, ra, disp21);
break;
case 0x38:
/* BLBC */
gen_bcond(ctx, TCG_COND_EQ, ra, disp21, 1);
ret = 1;
ret = gen_bcond(ctx, TCG_COND_EQ, ra, disp21, 1);
break;
case 0x39:
/* BEQ */
gen_bcond(ctx, TCG_COND_EQ, ra, disp21, 0);
ret = 1;
ret = gen_bcond(ctx, TCG_COND_EQ, ra, disp21, 0);
break;
case 0x3A:
/* BLT */
gen_bcond(ctx, TCG_COND_LT, ra, disp21, 0);
ret = 1;
ret = gen_bcond(ctx, TCG_COND_LT, ra, disp21, 0);
break;
case 0x3B:
/* BLE */
gen_bcond(ctx, TCG_COND_LE, ra, disp21, 0);
ret = 1;
ret = gen_bcond(ctx, TCG_COND_LE, ra, disp21, 0);
break;
case 0x3C:
/* BLBS */
gen_bcond(ctx, TCG_COND_NE, ra, disp21, 1);
ret = 1;
ret = gen_bcond(ctx, TCG_COND_NE, ra, disp21, 1);
break;
case 0x3D:
/* BNE */
gen_bcond(ctx, TCG_COND_NE, ra, disp21, 0);
ret = 1;
ret = gen_bcond(ctx, TCG_COND_NE, ra, disp21, 0);
break;
case 0x3E:
/* BGE */
gen_bcond(ctx, TCG_COND_GE, ra, disp21, 0);
ret = 1;
ret = gen_bcond(ctx, TCG_COND_GE, ra, disp21, 0);
break;
case 0x3F:
/* BGT */
gen_bcond(ctx, TCG_COND_GT, ra, disp21, 0);
ret = 1;
ret = gen_bcond(ctx, TCG_COND_GT, ra, disp21, 0);
break;
invalid_opc:
gen_invalid(ctx);
ret = 3;
/* PC updated by gen_excp. */
ret = EXIT_PC_UPDATED;
break;
}
@ -3051,15 +3091,17 @@ static inline void gen_intermediate_code_internal(CPUState *env,
uint16_t *gen_opc_end;
CPUBreakpoint *bp;
int j, lj = -1;
int ret;
ExitStatus ret;
int num_insns;
int max_insns;
pc_start = tb->pc;
gen_opc_end = gen_opc_buf + OPC_MAX_SIZE;
ctx.tb = tb;
ctx.env = env;
ctx.pc = pc_start;
ctx.amask = env->amask;
ctx.env = env;
#if defined (CONFIG_USER_ONLY)
ctx.mem_idx = 0;
#else
@ -3083,7 +3125,7 @@ static inline void gen_intermediate_code_internal(CPUState *env,
max_insns = CF_COUNT_MASK;
gen_icount_start();
for (ret = 0; ret == 0;) {
do {
if (unlikely(!QTAILQ_EMPTY(&env->breakpoints))) {
QTAILQ_FOREACH(bp, &env->breakpoints, entry) {
if (bp->pc == ctx.pc) {
@ -3114,36 +3156,39 @@ static inline void gen_intermediate_code_internal(CPUState *env,
ctx.pc += 4;
ret = translate_one(ctxp, insn);
if (ret != 0)
break;
/* if we reach a page boundary or are single stepping, stop
* generation
*/
if (ret == NO_EXIT) {
/* If we reach a page boundary, are single stepping,
or exhaust instruction count, stop generation. */
if (env->singlestep_enabled) {
gen_excp(&ctx, EXCP_DEBUG, 0);
break;
}
if ((ctx.pc & (TARGET_PAGE_SIZE - 1)) == 0)
break;
if (gen_opc_ptr >= gen_opc_end)
break;
if (num_insns >= max_insns)
break;
if (singlestep) {
break;
ret = EXIT_PC_UPDATED;
} else if ((ctx.pc & (TARGET_PAGE_SIZE - 1)) == 0
|| gen_opc_ptr >= gen_opc_end
|| num_insns >= max_insns
|| singlestep) {
ret = EXIT_PC_STALE;
}
}
if (ret != 1 && ret != 3) {
tcg_gen_movi_i64(cpu_pc, ctx.pc);
}
if (tb->cflags & CF_LAST_IO)
} while (ret == NO_EXIT);
if (tb->cflags & CF_LAST_IO) {
gen_io_end();
/* Generate the return instruction */
}
switch (ret) {
case EXIT_GOTO_TB:
break;
case EXIT_PC_STALE:
tcg_gen_movi_i64(cpu_pc, ctx.pc);
/* FALLTHRU */
case EXIT_PC_UPDATED:
tcg_gen_exit_tb(0);
break;
default:
abort();
}
gen_icount_end(tb, num_insns);
*gen_opc_ptr = INDEX_op_end;
if (search_pc) {
@ -3155,6 +3200,7 @@ static inline void gen_intermediate_code_internal(CPUState *env,
tb->size = ctx.pc - pc_start;
tb->icount = num_insns;
}
#ifdef DEBUG_DISAS
if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM)) {
qemu_log("IN: %s\n", lookup_symbol(pc_start));