From 80850da1e9e9866ff7792865bebea52114d0231c Mon Sep 17 00:00:00 2001 From: Segher Boessenkool Date: Mon, 4 Dec 2017 10:30:37 +0100 Subject: [PATCH] lra: Clobbers in a parallel are earlyclobbers (PR83245) The documentation (rtl.texi) says: When a @code{clobber} expression for a register appears inside a @code{parallel} with other side effects, the register allocator guarantees that the register is unoccupied both before and after that insn if it is a hard register clobber. and at least the rs6000 backend relies on that (see PR83245). This patch restores that behaviour. Registers that are also used as operands in the instruction are not treated as earlyclobber, so such insns also still work (PR80818, an s390 testcase). PR rtl-optimization/83245 * lra.c (collect_non_operand_hard_regs): Treat clobbers of non-operand hard registers as earlyclobber, also if not in an asm. From-SVN: r255377 --- gcc/ChangeLog | 6 ++++++ gcc/lra.c | 12 ++++-------- 2 files changed, 10 insertions(+), 8 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 95496132a2b..3b0f55ffe26 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2017-12-04 Segher Boessenkool + + PR rtl-optimization/83245 + * lra.c (collect_non_operand_hard_regs): Treat clobbers of non-operand + hard registers as earlyclobber, also if not in an asm. + 2017-12-04 Segher Boessenkool PR bootstrap/83265 diff --git a/gcc/lra.c b/gcc/lra.c index f49c50a4036..0d76eac3f3b 100644 --- a/gcc/lra.c +++ b/gcc/lra.c @@ -888,14 +888,10 @@ collect_non_operand_hard_regs (rtx_insn *insn, rtx *x, list, OP_IN, false); break; case CLOBBER: - { - int code = INSN_CODE (insn); - /* We treat clobber of non-operand hard registers as early - clobber (the behavior is expected from asm). */ - list = collect_non_operand_hard_regs (insn, &XEXP (op, 0), data, - list, OP_OUT, code < 0); - break; - } + /* We treat clobber of non-operand hard registers as early clobber. */ + list = collect_non_operand_hard_regs (insn, &XEXP (op, 0), data, + list, OP_OUT, true); + break; case PRE_INC: case PRE_DEC: case POST_INC: case POST_DEC: list = collect_non_operand_hard_regs (insn, &XEXP (op, 0), data, list, OP_INOUT, false); -- 2.30.2