On 5/3/21 1:57 AM, Richard Henderson wrote:
> This requires adjusting where arguments are stored.
> Place them on the stack at left-aligned positions.
> Adjust the stack frame to be at entirely positive offsets.
>
> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
> ---
> include/tcg/tcg.h | 1 +
> tcg/tci/tcg-target.h | 2 +-
> tcg/tcg.c | 64 +++++++++++++------
> tcg/tci.c | 135 ++++++++++++++++++++++-----------------
> tcg/tci/tcg-target.c.inc | 50 +++++++--------
> 5 files changed, 148 insertions(+), 104 deletions(-)
>
> diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h
> index 0f0695e90d..e5573a9877 100644
> --- a/include/tcg/tcg.h
> +++ b/include/tcg/tcg.h
> @@ -53,6 +53,7 @@
> #define MAX_OPC_PARAM (4 + (MAX_OPC_PARAM_PER_ARG * MAX_OPC_PARAM_ARGS))
>
> #define CPU_TEMP_BUF_NLONGS 128
> +#define TCG_STATIC_FRAME_SIZE (CPU_TEMP_BUF_NLONGS * sizeof(long))
>
> /* Default target word size to pointer size. */
> #ifndef TCG_TARGET_REG_BITS
> diff --git a/tcg/tci/tcg-target.h b/tcg/tci/tcg-target.h
> index 52af6d8bc5..4df10e2e83 100644
> --- a/tcg/tci/tcg-target.h
> +++ b/tcg/tci/tcg-target.h
> @@ -161,7 +161,7 @@ typedef enum {
>
> /* Used for function call generation. */
> #define TCG_TARGET_CALL_STACK_OFFSET 0
> -#define TCG_TARGET_STACK_ALIGN 16
> +#define TCG_TARGET_STACK_ALIGN 8
Is this FFI_SIZEOF_ARG?
>
> #define HAVE_TCG_QEMU_TB_EXEC
...
> static void tci_args_rr(const uint8_t **tb_ptr,
> TCGReg *r0, TCGReg *r1)
> {
> @@ -487,11 +479,13 @@ uintptr_t QEMU_DISABLE_CFI
> tcg_qemu_tb_exec(CPUArchState *env,
> {
> const uint8_t *tb_ptr = v_tb_ptr;
> tcg_target_ulong regs[TCG_TARGET_NB_REGS];
> - long tcg_temps[CPU_TEMP_BUF_NLONGS];
> - uintptr_t sp_value = (uintptr_t)(tcg_temps + CPU_TEMP_BUF_NLONGS);
> + uint64_t stack[(TCG_STATIC_CALL_ARGS_SIZE + TCG_STATIC_FRAME_SIZE)
> + / sizeof(uint64_t)];
Why not simply use a char* array? Ah I see later "call_slots[i] =
&stack[i];", OK.
> + void *call_slots[TCG_STATIC_CALL_ARGS_SIZE / sizeof(uint64_t)];
>
> regs[TCG_AREG0] = (tcg_target_ulong)env;
> - regs[TCG_REG_CALL_STACK] = sp_value;
> + regs[TCG_REG_CALL_STACK] = (uintptr_t)stack;
> + call_slots[0] = NULL;
Maybe add a comment "Other slots initialization delayed (see below)"?
> tci_assert(tb_ptr);
>
> for (;;) {
> @@ -509,40 +503,58 @@ uintptr_t QEMU_DISABLE_CFI
> tcg_qemu_tb_exec(CPUArchState *env,
> #endif
> TCGMemOpIdx oi;
> int32_t ofs;
> - void *ptr;
> + void *ptr, *cif;
>
> /* Skip opcode and size entry. */
> tb_ptr += 2;
>
> switch (opc) {
> case INDEX_op_call:
> - tci_args_l(&tb_ptr, &ptr);
> + /*
> + * Set up the ffi_avalue array once, delayed until now
> + * because many TB's do not make any calls. In tcg_gen_callN,
> + * we arranged for every real argument to be "left-aligned"
> + * in each 64-bit slot.
> + */
> + if (unlikely(call_slots[0] == NULL)) {
> + for (int i = 0; i < ARRAY_SIZE(call_slots); ++i) {
> + call_slots[i] = &stack[i];
> + }
> + }
> +
> + tci_args_nll(&tb_ptr, &len, &ptr, &cif);
Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org>
