From d252130b8e880f2f7f826217fe806da76fbcbb7c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Tue, 10 Apr 2012 12:28:11 +0200 Subject: Rewrite the hipe_mode_switch instructions The 'cmd' variable that were shared by several hipe_mode_switch instructions would cause clang to produce sub-optimal code, probably because it considered the instructions as part of of loop that needed to be optimized. What would was that 'cmd' would be assigned to the ESI register (lower 32 bits of the RSI register). It would use ESI for other purposes in instructions, but at the end of every instruction it would set ESI to 1 just in case the next instruction happened to be hipe_trap_return. This can be seen clearly if this commit is omitted and the define HIPE_MODE_SWITCH_CMD_RETURN in hipe/hipe_mode_switch.h is changed from 1 to some other number such as 42. You will see that 42 is assigned to ESI at the end of every instruction. Eliminate this problem by elimininating the shared 'cmd' variable. --- erts/emulator/beam/beam_emu.c | 32 +++++++++++++++----------------- 1 file changed, 15 insertions(+), 17 deletions(-) diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c index 7dbf14de02..362c6e4826 100644 --- a/erts/emulator/beam/beam_emu.c +++ b/erts/emulator/beam/beam_emu.c @@ -4681,7 +4681,12 @@ do { \ #ifdef HIPE { - unsigned cmd; +#define HIPE_MODE_SWITCH(Cmd) \ + SWAPOUT; \ + c_p->fcalls = FCALLS; \ + c_p->def_arg_reg[4] = -neg_o_reds; \ + c_p = hipe_mode_switch(c_p, Cmd, reg); \ + goto L_post_hipe_mode_switch OpCase(hipe_trap_call): { /* @@ -4695,38 +4700,31 @@ do { \ */ ASSERT(I[-5] == (Uint) OpCode(i_func_info_IaaI)); c_p->hipe.u.ncallee = (void(*)(void)) I[-4]; - cmd = HIPE_MODE_SWITCH_CMD_CALL | (I[-1] << 8); ++hipe_trap_count; - goto L_hipe_mode_switch; + HIPE_MODE_SWITCH(HIPE_MODE_SWITCH_CMD_CALL | (I[-1] << 8)); } OpCase(hipe_trap_call_closure): { ASSERT(I[-5] == (Uint) OpCode(i_func_info_IaaI)); c_p->hipe.u.ncallee = (void(*)(void)) I[-4]; - cmd = HIPE_MODE_SWITCH_CMD_CALL_CLOSURE | (I[-1] << 8); ++hipe_trap_count; - goto L_hipe_mode_switch; + HIPE_MODE_SWITCH(HIPE_MODE_SWITCH_CMD_CALL_CLOSURE | (I[-1] << 8)); } OpCase(hipe_trap_return): { - cmd = HIPE_MODE_SWITCH_CMD_RETURN; - goto L_hipe_mode_switch; + HIPE_MODE_SWITCH(HIPE_MODE_SWITCH_CMD_RETURN); } OpCase(hipe_trap_throw): { - cmd = HIPE_MODE_SWITCH_CMD_THROW; - goto L_hipe_mode_switch; + HIPE_MODE_SWITCH(HIPE_MODE_SWITCH_CMD_THROW); } OpCase(hipe_trap_resume): { - cmd = HIPE_MODE_SWITCH_CMD_RESUME; - goto L_hipe_mode_switch; + HIPE_MODE_SWITCH(HIPE_MODE_SWITCH_CMD_RESUME); } - L_hipe_mode_switch: - /* XXX: this abuse of def_arg_reg[] is horrid! */ - SWAPOUT; - c_p->fcalls = FCALLS; - c_p->def_arg_reg[4] = -neg_o_reds; - c_p = hipe_mode_switch(c_p, cmd, reg); +#undef HIPE_MODE_SWITCH + + L_post_hipe_mode_switch: reg = ERTS_PROC_GET_SCHDATA(c_p)->x_reg_array; freg = ERTS_PROC_GET_SCHDATA(c_p)->f_reg_array; ERL_BITS_RELOAD_STATEP(c_p); + /* XXX: this abuse of def_arg_reg[] is horrid! */ neg_o_reds = -c_p->def_arg_reg[4]; FCALLS = c_p->fcalls; SWAPIN; -- cgit v1.2.3