48 lines
1.5 KiB
Diff
48 lines
1.5 KiB
Diff
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From 9cd11fd48509234e18122036bf504981f5a91b9a Mon Sep 17 00:00:00 2001
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From: Richard Sandiford <richard.sandiford@arm.com>
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Date: Thu, 31 Aug 2023 11:59:56 +0100
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Subject: [PATCH] lra: Avoid unfolded plus-0
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To: gcc-patches@gcc.gnu.org
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While backporting another patch to an earlier release, I hit a
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situation in which lra_eliminate_regs_1 would eliminate an address to:
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(plus (reg:P R) (const_int 0))
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This address compared not-equal to plain:
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(reg:P R)
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which caused an ICE in a later peephole2. (The ICE showed up in
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gfortran.fortran-torture/compile/pr80464.f90 on the branch but seems
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to be latent on trunk.)
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These unfolded PLUSes shouldn't occur in the insn stream, and later code
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in the same function tried to avoid them.
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gcc/
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* lra-eliminations.cc (lra_eliminate_regs_1): Use simplify_gen_binary
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rather than gen_rtx_PLUS.
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---
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gcc/lra-eliminations.c | 4 ++--
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1 file changed, 2 insertions(+), 2 deletions(-)
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diff --git a/gcc/lra-eliminations.c b/gcc/lra-eliminations.c
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index 993da861cf9..a3daf443caf 100644
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--- a/gcc/lra-eliminations.c
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+++ b/gcc/lra-eliminations.c
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@@ -391,8 +391,8 @@ lra_eliminate_regs_1 (rtx_insn *insn, rtx x, machine_mode mem_mode,
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rtx to = subst_p ? ep->to_rtx : ep->from_rtx;
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if (! update_p && ! full_p)
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- return gen_rtx_PLUS (Pmode, to, XEXP (x, 1));
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-
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+ return simplify_gen_binary (PLUS, Pmode, to, XEXP (x, 1));
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+
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if (update_sp_offset != 0)
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offset = ep->to_rtx == stack_pointer_rtx ? update_sp_offset : 0;
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else
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--
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2.35.3
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