diff options
| author | Richard Henderson <richard.henderson@linaro.org> | 2021-08-05 02:23:05 +0300 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2022-02-09 09:00:00 +1100 |
| commit | e01d60f211251388a5d9ae7e02d0b4500af26966 (patch) | |
| tree | b18178d93c3ba38b3f0465ed808643b0da71d2fe /tcg | |
| parent | c834b8d81b0ee597d185a4d8127dfc76230307c8 (diff) | |
tcg/sparc: Add tcg_out_jmpl_const for better tail calls
Due to mapping changes, we now rarely place the code_gen_buffer
near the main executable. Which means that direct calls will
now rarely be in range.
So, always use indirect calls for tail calls, which allows us to
avoid clobbering %o7, and therefore we need not save and restore it.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'tcg')
| -rw-r--r-- | tcg/sparc/tcg-target.c.inc | 37 |
1 files changed, 23 insertions, 14 deletions
diff --git a/tcg/sparc/tcg-target.c.inc b/tcg/sparc/tcg-target.c.inc index e78945d153..646bb462c3 100644 --- a/tcg/sparc/tcg-target.c.inc +++ b/tcg/sparc/tcg-target.c.inc @@ -858,6 +858,19 @@ static void tcg_out_addsub2_i64(TCGContext *s, TCGReg rl, TCGReg rh, tcg_out_mov(s, TCG_TYPE_I64, rl, tmp); } +static void tcg_out_jmpl_const(TCGContext *s, const tcg_insn_unit *dest, + bool in_prologue, bool tail_call) +{ + uintptr_t desti = (uintptr_t)dest; + + /* Be careful not to clobber %o7 for a tail call. */ + tcg_out_movi_int(s, TCG_TYPE_PTR, TCG_REG_T1, + desti & ~0xfff, in_prologue, + tail_call ? TCG_REG_G2 : TCG_REG_O7); + tcg_out_arithi(s, tail_call ? TCG_REG_G0 : TCG_REG_O7, + TCG_REG_T1, desti & 0xfff, JMPL); +} + static void tcg_out_call_nodelay(TCGContext *s, const tcg_insn_unit *dest, bool in_prologue) { @@ -866,10 +879,7 @@ static void tcg_out_call_nodelay(TCGContext *s, const tcg_insn_unit *dest, if (disp == (int32_t)disp) { tcg_out32(s, CALL | (uint32_t)disp >> 2); } else { - uintptr_t desti = (uintptr_t)dest; - tcg_out_movi_int(s, TCG_TYPE_PTR, TCG_REG_T1, - desti & ~0xfff, in_prologue, TCG_REG_O7); - tcg_out_arithi(s, TCG_REG_O7, TCG_REG_T1, desti & 0xfff, JMPL); + tcg_out_jmpl_const(s, dest, in_prologue, false); } } @@ -960,11 +970,10 @@ static void build_trampolines(TCGContext *s) /* Set the retaddr operand. */ tcg_out_mov(s, TCG_TYPE_PTR, ra, TCG_REG_O7); - /* Set the env operand. */ - tcg_out_mov(s, TCG_TYPE_PTR, TCG_REG_O0, TCG_AREG0); /* Tail call. */ - tcg_out_call_nodelay(s, qemu_ld_helpers[i], true); - tcg_out_mov(s, TCG_TYPE_PTR, TCG_REG_O7, ra); + tcg_out_jmpl_const(s, qemu_ld_helpers[i], true, true); + /* delay slot -- set the env argument */ + tcg_out_mov_delay(s, TCG_REG_O0, TCG_AREG0); } for (i = 0; i < ARRAY_SIZE(qemu_st_helpers); ++i) { @@ -1006,14 +1015,14 @@ static void build_trampolines(TCGContext *s) if (ra >= TCG_REG_O6) { tcg_out_st(s, TCG_TYPE_PTR, TCG_REG_O7, TCG_REG_CALL_STACK, TCG_TARGET_CALL_STACK_OFFSET); - ra = TCG_REG_G1; + } else { + tcg_out_mov(s, TCG_TYPE_PTR, ra, TCG_REG_O7); } - tcg_out_mov(s, TCG_TYPE_PTR, ra, TCG_REG_O7); - /* Set the env operand. */ - tcg_out_mov(s, TCG_TYPE_PTR, TCG_REG_O0, TCG_AREG0); + /* Tail call. */ - tcg_out_call_nodelay(s, qemu_st_helpers[i], true); - tcg_out_mov(s, TCG_TYPE_PTR, TCG_REG_O7, ra); + tcg_out_jmpl_const(s, qemu_st_helpers[i], true, true); + /* delay slot -- set the env argument */ + tcg_out_mov_delay(s, TCG_REG_O0, TCG_AREG0); } } #endif |