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(reg_unused_after): For a SEQUENCE, make sure all insns are safe 

before returning 1.

From-SVN: r10261
This commit is contained in:
Richard Kenner 1995-08-21 13:04:26 -04:00
parent 32c5cac2a5
commit 8783b15e06
1 changed files with 38 additions and 11 deletions
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49
gcc/config/sh/sh.c
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@ -1868,7 +1868,7 @@ reg_unused_after (reg, insn)
rtx reg;
rtx insn;
{
enum rtx_code code, prev_code = UNKNOWN;
enum rtx_code code;
rtx set;
/* If the reg is set by this instruction, then it is safe for our
@ -1881,20 +1881,45 @@ reg_unused_after (reg, insn)
while (insn = NEXT_INSN (insn))
{
if (prev_code == CALL_INSN && call_used_regs[REGNO (reg)])
return 1;
code = GET_CODE (insn);
if (GET_CODE (insn) == CODE_LABEL)
if (code == CODE_LABEL)
return 1;
if (code == INSN && GET_CODE (PATTERN (insn)) == SEQUENCE)
/* If this is a sequence, we must handle them all at once.
We could have for instance a call that sets the target register,
and a insn in a delay slot that uses the register. In this case,
we must return 0. */
else if (code == INSN && GET_CODE (PATTERN (insn)) == SEQUENCE)
{
insn = XVECEXP (PATTERN (insn), 0, 0);
code = GET_CODE (insn);
}
int i;
int retval = 0;
if (GET_RTX_CLASS (code) == 'i')
for (i = 0; i < XVECLEN (PATTERN (insn), 0); i++)
{
rtx this_insn = XVECEXP (PATTERN (insn), 0, i);
rtx set = single_set (this_insn);
if (GET_CODE (this_insn) == CALL_INSN)
code = CALL_INSN;
if (set && reg_overlap_mentioned_p (reg, SET_SRC (set)))
return 0;
if (set && reg_overlap_mentioned_p (reg, SET_DEST (set)))
{
if (GET_CODE (SET_DEST (set)) != MEM)
retval = 1;
else
return 0;
}
if (set == 0
&& reg_overlap_mentioned_p (reg, PATTERN (this_insn)))
return 0;
}
if (retval == 1)
return 1;
}
else if (GET_RTX_CLASS (code) == 'i')
{
rtx set = single_set (insn);
@ -1905,7 +1930,9 @@ reg_unused_after (reg, insn)
if (set == 0 && reg_overlap_mentioned_p (reg, PATTERN (insn)))
return 0;
}
prev_code = code;
if (code == CALL_INSN && call_used_regs[REGNO (reg)])
return 1;
}
return 1;
}