tcg/riscv: Remove MO_BSWAP handling

TCG_TARGET_HAS_MEMORY_BSWAP is already unset for this backend,
which means that MO_BSWAP be handled by the middle-end and
will never be seen by the backend.  Thus the indexes used with
qemu_{ld,st}_helpers will always be zero.

Tidy the comments and asserts in tcg_out_qemu_{ld,st}_direct.
It is not that we do not handle bswap "yet", but never will.

Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2021-06-13 17:12:49 -07:00
parent 51c559c761
commit c86bd2dc4c

View File

@ -852,37 +852,43 @@ static void tcg_out_mb(TCGContext *s, TCGArg a0)
/* helper signature: helper_ret_ld_mmu(CPUState *env, target_ulong addr,
* TCGMemOpIdx oi, uintptr_t ra)
*/
static void * const qemu_ld_helpers[16] = {
[MO_UB] = helper_ret_ldub_mmu,
[MO_SB] = helper_ret_ldsb_mmu,
[MO_LEUW] = helper_le_lduw_mmu,
[MO_LESW] = helper_le_ldsw_mmu,
[MO_LEUL] = helper_le_ldul_mmu,
static void * const qemu_ld_helpers[8] = {
[MO_UB] = helper_ret_ldub_mmu,
[MO_SB] = helper_ret_ldsb_mmu,
#ifdef HOST_WORDS_BIGENDIAN
[MO_UW] = helper_be_lduw_mmu,
[MO_SW] = helper_be_ldsw_mmu,
[MO_UL] = helper_be_ldul_mmu,
#if TCG_TARGET_REG_BITS == 64
[MO_LESL] = helper_le_ldsl_mmu,
[MO_SL] = helper_be_ldsl_mmu,
#endif
[MO_LEQ] = helper_le_ldq_mmu,
[MO_BEUW] = helper_be_lduw_mmu,
[MO_BESW] = helper_be_ldsw_mmu,
[MO_BEUL] = helper_be_ldul_mmu,
[MO_Q] = helper_be_ldq_mmu,
#else
[MO_UW] = helper_le_lduw_mmu,
[MO_SW] = helper_le_ldsw_mmu,
[MO_UL] = helper_le_ldul_mmu,
#if TCG_TARGET_REG_BITS == 64
[MO_BESL] = helper_be_ldsl_mmu,
[MO_SL] = helper_le_ldsl_mmu,
#endif
[MO_Q] = helper_le_ldq_mmu,
#endif
[MO_BEQ] = helper_be_ldq_mmu,
};
/* helper signature: helper_ret_st_mmu(CPUState *env, target_ulong addr,
* uintxx_t val, TCGMemOpIdx oi,
* uintptr_t ra)
*/
static void * const qemu_st_helpers[16] = {
[MO_UB] = helper_ret_stb_mmu,
[MO_LEUW] = helper_le_stw_mmu,
[MO_LEUL] = helper_le_stl_mmu,
[MO_LEQ] = helper_le_stq_mmu,
[MO_BEUW] = helper_be_stw_mmu,
[MO_BEUL] = helper_be_stl_mmu,
[MO_BEQ] = helper_be_stq_mmu,
static void * const qemu_st_helpers[4] = {
[MO_8] = helper_ret_stb_mmu,
#ifdef HOST_WORDS_BIGENDIAN
[MO_16] = helper_be_stw_mmu,
[MO_32] = helper_be_stl_mmu,
[MO_64] = helper_be_stq_mmu,
#else
[MO_16] = helper_le_stw_mmu,
[MO_32] = helper_le_stl_mmu,
[MO_64] = helper_le_stq_mmu,
#endif
};
/* We don't support oversize guests */
@ -997,7 +1003,7 @@ static bool tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
tcg_out_movi(s, TCG_TYPE_PTR, a2, oi);
tcg_out_movi(s, TCG_TYPE_PTR, a3, (tcg_target_long)l->raddr);
tcg_out_call(s, qemu_ld_helpers[opc & (MO_BSWAP | MO_SSIZE)]);
tcg_out_call(s, qemu_ld_helpers[opc & MO_SSIZE]);
tcg_out_mov(s, (opc & MO_SIZE) == MO_64, l->datalo_reg, a0);
tcg_out_goto(s, l->raddr);
@ -1042,7 +1048,7 @@ static bool tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
tcg_out_movi(s, TCG_TYPE_PTR, a3, oi);
tcg_out_movi(s, TCG_TYPE_PTR, a4, (tcg_target_long)l->raddr);
tcg_out_call(s, qemu_st_helpers[opc & (MO_BSWAP | MO_SSIZE)]);
tcg_out_call(s, qemu_st_helpers[opc & MO_SIZE]);
tcg_out_goto(s, l->raddr);
return true;
@ -1052,10 +1058,8 @@ static bool tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg lo, TCGReg hi,
TCGReg base, MemOp opc, bool is_64)
{
const MemOp bswap = opc & MO_BSWAP;
/* We don't yet handle byteswapping, assert */
g_assert(!bswap);
/* Byte swapping is left to middle-end expansion. */
tcg_debug_assert((opc & MO_BSWAP) == 0);
switch (opc & (MO_SSIZE)) {
case MO_UB:
@ -1139,10 +1143,8 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, bool is_64)
static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg lo, TCGReg hi,
TCGReg base, MemOp opc)
{
const MemOp bswap = opc & MO_BSWAP;
/* We don't yet handle byteswapping, assert */
g_assert(!bswap);
/* Byte swapping is left to middle-end expansion. */
tcg_debug_assert((opc & MO_BSWAP) == 0);
switch (opc & (MO_SSIZE)) {
case MO_8: