From 6b4f5050a9a5156eb23b9174ff576a77b1149465 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Sat, 1 Dec 2018 08:27:58 +0100 Subject: re PR target/54589 (struct offset add should be folded into address calculation) PR target/54589 * combine.c (find_split_point): For invalid memory address nonobj + obj + const, if reg + obj + const is valid addressing mode, split at nonobj. Use if rather than else if for the fallback. Comment fixes. * gcc.target/i386/pr54589.c: New test. From-SVN: r266707 --- gcc/combine.c | 49 +++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 43 insertions(+), 6 deletions(-) (limited to 'gcc/combine.c') diff --git a/gcc/combine.c b/gcc/combine.c index ecc83f89bce..7e611399f2c 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -4945,7 +4945,7 @@ find_split_point (rtx *loc, rtx_insn *insn, bool set_src) } /* If we have a PLUS whose second operand is a constant and the - address is not valid, perhaps will can split it up using + address is not valid, perhaps we can split it up using the machine-specific way to split large constants. We use the first pseudo-reg (one of the virtual regs) as a placeholder; it will not remain in the result. */ @@ -4960,7 +4960,7 @@ find_split_point (rtx *loc, rtx_insn *insn, bool set_src) /* This should have produced two insns, each of which sets our placeholder. If the source of the second is a valid address, - we can make put both sources together and make a split point + we can put both sources together and make a split point in the middle. */ if (seq @@ -5001,14 +5001,51 @@ find_split_point (rtx *loc, rtx_insn *insn, bool set_src) } } + /* If that didn't work and we have a nested plus, like: + ((REG1 * CONST1) + REG2) + CONST2 and (REG1 + REG2) + CONST2 + is valid address, try to split (REG1 * CONST1). */ + if (GET_CODE (XEXP (XEXP (x, 0), 0)) == PLUS + && !OBJECT_P (XEXP (XEXP (XEXP (x, 0), 0), 0)) + && OBJECT_P (XEXP (XEXP (XEXP (x, 0), 0), 1)) + && ! (GET_CODE (XEXP (XEXP (XEXP (x, 0), 0), 0)) == SUBREG + && OBJECT_P (SUBREG_REG (XEXP (XEXP (XEXP (x, 0), + 0), 0))))) + { + rtx tem = XEXP (XEXP (XEXP (x, 0), 0), 0); + XEXP (XEXP (XEXP (x, 0), 0), 0) = reg; + if (memory_address_addr_space_p (GET_MODE (x), XEXP (x, 0), + MEM_ADDR_SPACE (x))) + { + XEXP (XEXP (XEXP (x, 0), 0), 0) = tem; + return &XEXP (XEXP (XEXP (x, 0), 0), 0); + } + XEXP (XEXP (XEXP (x, 0), 0), 0) = tem; + } + else if (GET_CODE (XEXP (XEXP (x, 0), 0)) == PLUS + && OBJECT_P (XEXP (XEXP (XEXP (x, 0), 0), 0)) + && !OBJECT_P (XEXP (XEXP (XEXP (x, 0), 0), 1)) + && ! (GET_CODE (XEXP (XEXP (XEXP (x, 0), 0), 1)) == SUBREG + && OBJECT_P (SUBREG_REG (XEXP (XEXP (XEXP (x, 0), + 0), 1))))) + { + rtx tem = XEXP (XEXP (XEXP (x, 0), 0), 1); + XEXP (XEXP (XEXP (x, 0), 0), 1) = reg; + if (memory_address_addr_space_p (GET_MODE (x), XEXP (x, 0), + MEM_ADDR_SPACE (x))) + { + XEXP (XEXP (XEXP (x, 0), 0), 1) = tem; + return &XEXP (XEXP (XEXP (x, 0), 0), 1); + } + XEXP (XEXP (XEXP (x, 0), 0), 1) = tem; + } + /* If that didn't work, perhaps the first operand is complex and needs to be computed separately, so make a split point there. This will occur on machines that just support REG + CONST and have a constant moved through some previous computation. */ - - else if (!OBJECT_P (XEXP (XEXP (x, 0), 0)) - && ! (GET_CODE (XEXP (XEXP (x, 0), 0)) == SUBREG - && OBJECT_P (SUBREG_REG (XEXP (XEXP (x, 0), 0))))) + if (!OBJECT_P (XEXP (XEXP (x, 0), 0)) + && ! (GET_CODE (XEXP (XEXP (x, 0), 0)) == SUBREG + && OBJECT_P (SUBREG_REG (XEXP (XEXP (x, 0), 0))))) return &XEXP (XEXP (x, 0), 0); } -- cgit v1.2.3