From e181ffc92a355d1854a413f27354e519f93e126a Mon Sep 17 00:00:00 2001 From: Michael Meissner Date: Mon, 3 Feb 2020 18:25:07 -0500 Subject: [PATCH] Optimize vec_extract of vectors in memory with a PC-relative address. 2020-02-03 Michael Meissner * config/rs6000/rs6000.c (adjust_vec_address_pcrel): New helper function to adjust PC-relative vector addresses. (rs6000_adjust_vec_address): Call adjust_vec_address_pcrel to handle vectors with PC-relative addresses. --- gcc/ChangeLog | 7 +++++ gcc/config/rs6000/rs6000.c | 59 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 66 insertions(+) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 927968f7169..350f18d1161 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2020-02-03 Michael Meissner + + * config/rs6000/rs6000.c (adjust_vec_address_pcrel): New helper + function to adjust PC-relative vector addresses. + (rs6000_adjust_vec_address): Call adjust_vec_address_pcrel to + handle vectors with PC-relative addresses. + 2020-02-03 Michael Meissner * config/rs6000/rs6000.c (reg_to_non_prefixed): Add forward diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c index 0cd9cd174a5..bf0dc97405e 100644 --- a/gcc/config/rs6000/rs6000.c +++ b/gcc/config/rs6000/rs6000.c @@ -6767,6 +6767,60 @@ get_vector_offset (rtx mem, rtx element, rtx base_tmp, unsigned scalar_size) return base_tmp; } +/* Helper function update PC-relative addresses when we are adjusting a memory + address (ADDR) to a vector to point to a scalar field within the vector with + a constant offset (ELEMENT_OFFSET). If the address is not valid, we can + use the base register temporary (BASE_TMP) to form the address. */ + +static rtx +adjust_vec_address_pcrel (rtx addr, rtx element_offset, rtx base_tmp) +{ + rtx new_addr = NULL; + + gcc_assert (CONST_INT_P (element_offset)); + + if (GET_CODE (addr) == CONST) + addr = XEXP (addr, 0); + + if (GET_CODE (addr) == PLUS) + { + rtx op0 = XEXP (addr, 0); + rtx op1 = XEXP (addr, 1); + + if (CONST_INT_P (op1)) + { + HOST_WIDE_INT offset + = INTVAL (XEXP (addr, 1)) + INTVAL (element_offset); + + if (offset == 0) + new_addr = op0; + + else + { + rtx plus = gen_rtx_PLUS (Pmode, op0, GEN_INT (offset)); + new_addr = gen_rtx_CONST (Pmode, plus); + } + } + + else + { + emit_move_insn (base_tmp, addr); + new_addr = gen_rtx_PLUS (Pmode, base_tmp, element_offset); + } + } + + else if (SYMBOL_REF_P (addr) || LABEL_REF_P (addr)) + { + rtx plus = gen_rtx_PLUS (Pmode, addr, element_offset); + new_addr = gen_rtx_CONST (Pmode, plus); + } + + else + gcc_unreachable (); + + return new_addr; +} + /* Adjust a memory address (MEM) of a vector type to point to a scalar field within the vector (ELEMENT) with a mode (SCALAR_MODE). Use a base register temporary (BASE_TMP) to fixup the address. Return the new memory address @@ -6807,6 +6861,11 @@ rs6000_adjust_vec_address (rtx scalar_reg, else if (REG_P (addr) || SUBREG_P (addr)) new_addr = gen_rtx_PLUS (Pmode, addr, element_offset); + /* For references to local static variables, fold a constant offset into the + address. */ + else if (pcrel_local_address (addr, Pmode) && CONST_INT_P (element_offset)) + new_addr = adjust_vec_address_pcrel (addr, element_offset, base_tmp); + /* Optimize D-FORM addresses with constant offset with a constant element, to include the element offset in the address directly. */ else if (GET_CODE (addr) == PLUS) -- 2.30.2