From 3bd2918594dae34ae84f802747471445a976af09 Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Mon, 30 Sep 2019 16:20:26 +0000 Subject: [PATCH] Remove global call sets: cselib.c cselib_invalidate_regno is a no-op if REG_VALUES (i) is null, so we can check that first. Then, if we know what mode the register currently has, we can check whether it's clobbered in that mode. Using GET_MODE (values->elt->val_rtx) to get the mode of the last set is taken from cselib_reg_set_mode. 2019-09-30 Richard Sandiford gcc/ * cselib.c (cselib_process_insn): If we know what mode a register was set in, check whether it is clobbered in that mode by a call. Only fall back to reg_raw_mode if that fails. From-SVN: r276318 --- gcc/ChangeLog | 6 ++++++ gcc/cselib.c | 24 ++++++++++++++++++------ 2 files changed, 24 insertions(+), 6 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 181fd8056e0..5440a339ca6 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2019-09-30 Richard Sandiford + + * cselib.c (cselib_process_insn): If we know what mode a + register was set in, check whether it is clobbered in that + mode by a call. Only fall back to reg_raw_mode if that fails. + 2019-09-30 Richard Sandiford * cse.c: Include regs.h and function-abi.h. diff --git a/gcc/cselib.c b/gcc/cselib.c index 5de14a07317..36f649de79c 100644 --- a/gcc/cselib.c +++ b/gcc/cselib.c @@ -2768,12 +2768,24 @@ cselib_process_insn (rtx_insn *insn) { function_abi callee_abi = insn_callee_abi (insn); for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) - if (call_used_or_fixed_reg_p (i) - || (REG_VALUES (i) && REG_VALUES (i)->elt - && (targetm.hard_regno_call_part_clobbered - (callee_abi.id (), i, - GET_MODE (REG_VALUES (i)->elt->val_rtx))))) - cselib_invalidate_regno (i, reg_raw_mode[i]); + if (elt_list *values = REG_VALUES (i)) + { + /* If we know what mode the value was set in, check whether + it is still available after the call in that mode. If we + don't know the mode, we have to check for the worst-case + scenario instead. */ + if (values->elt) + { + machine_mode mode = GET_MODE (values->elt->val_rtx); + if (callee_abi.clobbers_reg_p (mode, i)) + cselib_invalidate_regno (i, mode); + } + else + { + if (callee_abi.clobbers_at_least_part_of_reg_p (i)) + cselib_invalidate_regno (i, reg_raw_mode[i]); + } + } /* Since it is not clear how cselib is going to be used, be conservative here and treat looping pure or const functions -- 2.30.2