tcg/tci: Implement goto_ptr

This operation is critical to staying within the interpretation
loop longer, which avoids the overhead of setup and teardown for
many TBs.

The check in tcg_prologue_init is disabled because TCI does
want to use NULL to indicate exit, as opposed to branching to
a real epilogue.

Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2021-02-02 09:40:22 -10:00
parent 6508988918
commit 6eea04347e
5 changed files with 44 additions and 2 deletions

View File

@ -785,10 +785,16 @@ void tcg_prologue_init(TCGContext *s)
}
#endif
/* Assert that goto_ptr is implemented completely. */
#ifndef CONFIG_TCG_INTERPRETER
/*
* Assert that goto_ptr is implemented completely, setting an epilogue.
* For tci, we use NULL as the signal to return from the interpreter,
* so skip this check.
*/
if (TCG_TARGET_HAS_goto_ptr) {
tcg_debug_assert(tcg_code_gen_epilogue != NULL);
}
#endif
}
void tcg_func_start(TCGContext *s)

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@ -73,6 +73,11 @@ static void tci_args_l(uint32_t insn, const void *tb_ptr, void **l0)
*l0 = diff ? (void *)tb_ptr + diff : NULL;
}
static void tci_args_r(uint32_t insn, TCGReg *r0)
{
*r0 = extract32(insn, 8, 4);
}
static void tci_args_nl(uint32_t insn, const void *tb_ptr,
uint8_t *n0, void **l1)
{
@ -739,6 +744,15 @@ uintptr_t QEMU_DISABLE_CFI tcg_qemu_tb_exec(CPUArchState *env,
tb_ptr = *(void **)ptr;
break;
case INDEX_op_goto_ptr:
tci_args_r(insn, &r0);
ptr = (void *)regs[r0];
if (!ptr) {
return 0;
}
tb_ptr = ptr;
break;
case INDEX_op_qemu_ld_i32:
if (TARGET_LONG_BITS <= TCG_TARGET_REG_BITS) {
tci_args_rrm(insn, &r0, &r1, &oi);
@ -996,6 +1010,11 @@ int print_insn_tci(bfd_vma addr, disassemble_info *info)
info->fprintf_func(info->stream, "%-12s %p", op_name, ptr);
break;
case INDEX_op_goto_ptr:
tci_args_r(insn, &r0);
info->fprintf_func(info->stream, "%-12s %s", op_name, str_r(r0));
break;
case INDEX_op_call:
tci_args_nl(insn, tb_ptr, &len, &ptr);
info->fprintf_func(info->stream, "%-12s %d, %p", op_name, len, ptr);

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@ -9,6 +9,7 @@
* Each operand should be a sequence of constraint letters as defined by
* tcg-target-con-str.h; the constraint combination is inclusive or.
*/
C_O0_I1(r)
C_O0_I2(r, r)
C_O0_I3(r, r, r)
C_O0_I4(r, r, r, r)

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@ -27,6 +27,9 @@
static TCGConstraintSetIndex tcg_target_op_def(TCGOpcode op)
{
switch (op) {
case INDEX_op_goto_ptr:
return C_O0_I1(r);
case INDEX_op_ld8u_i32:
case INDEX_op_ld8s_i32:
case INDEX_op_ld16u_i32:
@ -263,6 +266,15 @@ static void tcg_out_op_p(TCGContext *s, TCGOpcode op, void *p0)
tcg_out32(s, insn);
}
static void tcg_out_op_r(TCGContext *s, TCGOpcode op, TCGReg r0)
{
tcg_insn_unit insn = 0;
insn = deposit32(insn, 0, 8, op);
insn = deposit32(insn, 8, 4, r0);
tcg_out32(s, insn);
}
static void tcg_out_op_v(TCGContext *s, TCGOpcode op)
{
tcg_out32(s, (uint8_t)op);
@ -565,6 +577,10 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc,
set_jmp_reset_offset(s, args[0]);
break;
case INDEX_op_goto_ptr:
tcg_out_op_r(s, opc, args[0]);
break;
case INDEX_op_br:
tcg_out_op_l(s, opc, arg_label(args[0]));
break;

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@ -87,7 +87,7 @@
#define TCG_TARGET_HAS_muls2_i32 0
#define TCG_TARGET_HAS_muluh_i32 0
#define TCG_TARGET_HAS_mulsh_i32 0
#define TCG_TARGET_HAS_goto_ptr 0
#define TCG_TARGET_HAS_goto_ptr 1
#define TCG_TARGET_HAS_direct_jump 0
#define TCG_TARGET_HAS_qemu_st8_i32 0