The reg_set_p part is simple, since the caller is asking about
a specific REG rtx, with a known register number and mode.
The find_all_hard_reg_sets part emphasises that the "implicit"
behaviour was always a bit suspect, since it includes fully-clobbered
registers but not partially-clobbered registers. The only current
user of this path is the c6x-specific scheduler predication code,
and c6x doesn't have partly call-clobbered registers, so in practice
it's fine. I've added a comment to try to disuade future users.
(The !implicit path is OK and useful though.)
2019-09-11 Richard Sandiford <richard.sandif...@arm.com>
gcc/
* rtlanal.c: Include function-abi.h.
(reg_set_p): Use call_insn_abi to get the ABI of the called
function and clobbers_reg_p to test whether the register
is call-clobbered.
(find_all_hard_reg_sets): When implicit is true, use call_insn_abi
to get the ABI of the called function and full_reg_clobbers to
get the set of fully call-clobbered registers. Warn about the
pitfalls of using this mode.
Index: gcc/rtlanal.c
===================================================================
--- gcc/rtlanal.c 2019-09-11 19:47:24.418262673 +0100
+++ gcc/rtlanal.c 2019-09-11 19:49:04.417558020 +0100
@@ -36,6 +36,7 @@ Software Foundation; either version 3, o
#include "addresses.h"
#include "rtl-iter.h"
#include "hard-reg-set.h"
+#include "function-abi.h"
/* Forward declarations */
static void set_of_1 (rtx, const_rtx, void *);
@@ -1270,8 +1271,8 @@ reg_set_p (const_rtx reg, const_rtx insn
|| (CALL_P (insn)
&& ((REG_P (reg)
&& REGNO (reg) < FIRST_PSEUDO_REGISTER
- && overlaps_hard_reg_set_p (regs_invalidated_by_call,
- GET_MODE (reg), REGNO (reg)))
+ && (call_insn_abi (as_a<const rtx_insn *> (insn))
+ .clobbers_reg_p (GET_MODE (reg), REGNO (reg))))
|| MEM_P (reg)
|| find_reg_fusage (insn, CLOBBER, reg)))))
return true;
@@ -1486,7 +1487,11 @@ record_hard_reg_sets (rtx x, const_rtx p
}
/* Examine INSN, and compute the set of hard registers written by it.
- Store it in *PSET. Should only be called after reload. */
+ Store it in *PSET. Should only be called after reload.
+
+ IMPLICIT is true if we should include registers that are fully-clobbered
+ by calls. This should be used with caution, since it doesn't include
+ partially-clobbered registers. */
void
find_all_hard_reg_sets (const rtx_insn *insn, HARD_REG_SET *pset, bool
implicit)
{
@@ -1495,7 +1500,7 @@ find_all_hard_reg_sets (const rtx_insn *
CLEAR_HARD_REG_SET (*pset);
note_stores (insn, record_hard_reg_sets, pset);
if (CALL_P (insn) && implicit)
- *pset |= call_used_or_fixed_regs;
+ *pset |= call_insn_abi (insn).full_reg_clobbers ();
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
if (REG_NOTE_KIND (link) == REG_INC)
record_hard_reg_sets (XEXP (link, 0), NULL, pset);
