Sync with external/gpl3/gcc:

https://mail-index.netbsd.org/source-changes/2023/07/18/msg146078.html
----
gcc: Fix peephole optimization bug for sh3 (PR port-sh3/56311)

Cherry-picked from upstream:
https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=4dbb3af1efe55174a714d15c2994cf2842ef8c28
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101469

Now, the PR confirmed fixed. No regression observed for full ATF run on
landisk (compared with GCC built with this peephole optimization being
removed by hand).

We thank Oleg Endo, the author of the upstream commit.

Also thanks hgutch@ and uwe@ for analysis.
This commit is contained in:
rin 2023-07-18 02:58:38 +00:00
parent 81c70943e9
commit 40faff9771
1 changed files with 39 additions and 0 deletions

View File

@ -10681,6 +10681,45 @@
&& peep2_reg_dead_p (2, operands[1]) && peep2_reg_dead_p (3, operands[0])"
[(const_int 0)]
{
if (MEM_P (operands[3]) && reg_overlap_mentioned_p (operands[0], operands[3]))
{
// Take care when the eliminated operand[0] register is part of
// the destination memory address.
rtx addr = XEXP (operands[3], 0);
if (REG_P (addr))
operands[3] = replace_equiv_address (operands[3], operands[1]);
else if (GET_CODE (addr) == PLUS && REG_P (XEXP (addr, 0))
&& CONST_INT_P (XEXP (addr, 1))
&& REGNO (operands[0]) == REGNO (XEXP (addr, 0)))
operands[3] = replace_equiv_address (operands[3],
gen_rtx_PLUS (SImode, operands[1], XEXP (addr, 1)));
else if (GET_CODE (addr) == PLUS && REG_P (XEXP (addr, 0))
&& REG_P (XEXP (addr, 1)))
{
// register + register address @(R0, Rn)
// can change only the Rn in the address, not R0.
if (REGNO (operands[0]) == REGNO (XEXP (addr, 0))
&& REGNO (XEXP (addr, 0)) != 0)
{
operands[3] = replace_equiv_address (operands[3],
gen_rtx_PLUS (SImode, operands[1], XEXP (addr, 1)));
}
else if (REGNO (operands[0]) == REGNO (XEXP (addr, 1))
&& REGNO (XEXP (addr, 1)) != 0)
{
operands[3] = replace_equiv_address (operands[3],
gen_rtx_PLUS (SImode, XEXP (addr, 0), operands[1]));
}
else
FAIL;
}
else
FAIL;
}
emit_insn (gen_addsi3 (operands[1], operands[1], operands[2]));
sh_peephole_emit_move_insn (operands[3], operands[1]);
})