From 311b62ce0310876fbffeeaab0b50707242b3e663 Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Mon, 30 Sep 2019 16:20:23 +0000 Subject: [PATCH] Remove global call sets: cse.c Like with the combine.c patch, this one keeps things simple by invalidating values in partially-clobbered registers, rather than trying to tell whether the value in a partially-clobbered register is actually clobbered or not. Again, this is in principle a bug fix, but probably never matters in practice. 2019-09-30 Richard Sandiford gcc/ * cse.c: Include regs.h and function-abi.h. (invalidate_for_call): Take the call insn as an argument. Use insn_callee_abi to get the ABI of the call and invalidate partially clobbered registers as well as fully clobbered ones. (cse_insn): Update call accordingly. From-SVN: r276317 --- gcc/ChangeLog | 8 ++++++++ gcc/cse.c | 43 ++++++++++++++++++++++++------------------- 2 files changed, 32 insertions(+), 19 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index ed08c19bb40..181fd8056e0 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2019-09-30 Richard Sandiford + + * cse.c: Include regs.h and function-abi.h. + (invalidate_for_call): Take the call insn as an argument. + Use insn_callee_abi to get the ABI of the call and invalidate + partially clobbered registers as well as fully clobbered ones. + (cse_insn): Update call accordingly. + 2019-09-30 Richard Sandiford * combine.c: Include function-abi.h. diff --git a/gcc/cse.c b/gcc/cse.c index 32b67902451..be3277b8660 100644 --- a/gcc/cse.c +++ b/gcc/cse.c @@ -42,6 +42,8 @@ along with GCC; see the file COPYING3. If not see #include "tree-pass.h" #include "dbgcnt.h" #include "rtl-iter.h" +#include "regs.h" +#include "function-abi.h" /* The basic idea of common subexpression elimination is to go through the code, keeping a record of expressions that would @@ -566,7 +568,6 @@ static void remove_invalid_subreg_refs (unsigned int, poly_uint64, machine_mode); static void rehash_using_reg (rtx); static void invalidate_memory (void); -static void invalidate_for_call (void); static rtx use_related_value (rtx, struct table_elt *); static inline unsigned canon_hash (rtx, machine_mode); @@ -2091,23 +2092,31 @@ rehash_using_reg (rtx x) } /* Remove from the hash table any expression that is a call-clobbered - register. Also update their TICK values. */ + register in INSN. Also update their TICK values. */ static void -invalidate_for_call (void) +invalidate_for_call (rtx_insn *insn) { - unsigned int regno, endregno; - unsigned int i; + unsigned int regno; unsigned hash; struct table_elt *p, *next; int in_table = 0; hard_reg_set_iterator hrsi; - /* Go through all the hard registers. For each that is clobbered in - a CALL_INSN, remove the register from quantity chains and update + /* Go through all the hard registers. For each that might be clobbered + in call insn INSN, remove the register from quantity chains and update reg_tick if defined. Also see if any of these registers is currently - in the table. */ - EXECUTE_IF_SET_IN_HARD_REG_SET (regs_invalidated_by_call, 0, regno, hrsi) + in the table. + + ??? We could be more precise for partially-clobbered registers, + and only invalidate values that actually occupy the clobbered part + of the registers. It doesn't seem worth the effort though, since + we shouldn't see this situation much before RA. Whatever choice + we make here has to be consistent with the table walk below, + so any change to this test will require a change there too. */ + HARD_REG_SET callee_clobbers + = insn_callee_abi (insn).full_and_partial_reg_clobbers (); + EXECUTE_IF_SET_IN_HARD_REG_SET (callee_clobbers, 0, regno, hrsi) { delete_reg_equiv (regno); if (REG_TICK (regno) >= 0) @@ -2132,15 +2141,11 @@ invalidate_for_call (void) || REGNO (p->exp) >= FIRST_PSEUDO_REGISTER) continue; - regno = REGNO (p->exp); - endregno = END_REGNO (p->exp); - - for (i = regno; i < endregno; i++) - if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i)) - { - remove_from_table (p, hash); - break; - } + /* This must use the same test as above rather than the + more accurate clobbers_reg_p. */ + if (overlaps_hard_reg_set_p (callee_clobbers, GET_MODE (p->exp), + REGNO (p->exp))) + remove_from_table (p, hash); } } @@ -5823,7 +5828,7 @@ cse_insn (rtx_insn *insn) if (GET_CODE (XEXP (tem, 0)) == USE && MEM_P (XEXP (XEXP (tem, 0), 0))) invalidate (XEXP (XEXP (tem, 0), 0), VOIDmode); - invalidate_for_call (); + invalidate_for_call (insn); } /* Now invalidate everything set by this instruction. -- 2.30.2