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When clobbering a reg, check for later words of a multi word reg value

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From-SVN: r13899
This commit is contained in:
Ian Lance Taylor 1997-04-14 01:03:03 +00:00
parent a22ad97227
commit ba325ebaef
1 changed files with 37 additions and 0 deletions
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37
gcc/reload1.c
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@ -7551,6 +7551,12 @@ count_occurrences (x, find)
static rtx *reg_values;
/* This is a preallocated REG rtx which we use as a temporary in
reload_cse_invalidate_regno, so that we don't need to allocate a
new one each time through a loop in that function. */
static rtx invalidate_regno_rtx;
/* Invalidate any entries in reg_values which depend on REGNO,
including those for REGNO itself. This is called if REGNO is
changing. If CLOBBER is true, then always forget anything we
@ -7608,6 +7614,33 @@ reload_cse_invalidate_regno (regno, mode, clobber)
}
}
}
/* We must look at earlier registers, in case REGNO is part of a
multi word value but is not the first register. If an earlier
register has a value in a mode which overlaps REGNO, then we must
invalidate that earlier register. Note that we do not need to
check REGNO or later registers (we must not check REGNO itself,
because we would incorrectly conclude that there was a conflict). */
for (i = 0; i < regno; i++)
{
rtx x;
for (x = reg_values[i]; x; x = XEXP (x, 1))
{
if (XEXP (x, 0) != 0)
{
PUT_MODE (invalidate_regno_rtx, GET_MODE (XEXP (x, 0)));
REGNO (invalidate_regno_rtx) = i;
if (refers_to_regno_p (regno, endregno, invalidate_regno_rtx,
NULL_PTR))
{
reload_cse_invalidate_regno (i, VOIDmode, 1);
break;
}
}
}
}
}
/* The memory at address (plus MEM_BASE MEM_OFFSET), where MEM_OFFSET
@ -7800,6 +7833,10 @@ reload_cse_regs (first)
memory for a non-const call instruction. */
callmem = gen_rtx (MEM, BLKmode, const0_rtx);
/* This is used in reload_cse_invalidate_regno to avoid consing a
new REG in a loop in that function. */
invalidate_regno_rtx = gen_rtx (REG, VOIDmode, 0);
for (insn = first; insn; insn = NEXT_INSN (insn))
{
rtx body;