diff options
Diffstat (limited to 'gcc/ira.cc')
| -rw-r--r-- | gcc/ira.cc | 84 |
1 files changed, 83 insertions, 1 deletions
@@ -2113,6 +2113,87 @@ ira_get_dup_out_num (int op_num, alternative_mask alts, +/* Return true if a replacement of SRC by DEST does not lead to unsatisfiable + asm. A replacement is valid if SRC or DEST are not constrained in asm + inputs of a single asm statement. See match_asm_constraints_2() for more + details. TODO: As in match_asm_constraints_2() consider alternatives more + precisely. */ + +static bool +valid_replacement_for_asm_input_p_1 (const_rtx asmops, const_rtx src, const_rtx dest) +{ + int ninputs = ASM_OPERANDS_INPUT_LENGTH (asmops); + rtvec inputs = ASM_OPERANDS_INPUT_VEC (asmops); + for (int i = 0; i < ninputs; ++i) + { + rtx input_src = RTVEC_ELT (inputs, i); + const char *constraint_src + = ASM_OPERANDS_INPUT_CONSTRAINT (asmops, i); + if (rtx_equal_p (input_src, src) + && strchr (constraint_src, '{') != nullptr) + for (int j = 0; j < ninputs; ++j) + { + rtx input_dest = RTVEC_ELT (inputs, j); + const char *constraint_dest + = ASM_OPERANDS_INPUT_CONSTRAINT (asmops, j); + if (rtx_equal_p (input_dest, dest) + && strchr (constraint_dest, '{') != nullptr) + return false; + } + } + return true; +} + +/* Return true if a replacement of SRC by DEST does not lead to unsatisfiable + asm. A replacement is valid if SRC or DEST are not constrained in asm + inputs of a single asm statement. The final check is done in function + valid_replacement_for_asm_input_p_1. */ + +static bool +valid_replacement_for_asm_input_p (const_rtx src, const_rtx dest) +{ + /* Bail out early if there is no asm statement. */ + if (!crtl->has_asm_statement) + return true; + for (df_ref use = DF_REG_USE_CHAIN (REGNO (src)); + use; + use = DF_REF_NEXT_REG (use)) + { + struct df_insn_info *use_info = DF_REF_INSN_INFO (use); + /* Only check real uses, not artificial ones. */ + if (use_info) + { + rtx_insn *insn = DF_REF_INSN (use); + rtx pat = PATTERN (insn); + if (asm_noperands (pat) <= 0) + continue; + if (GET_CODE (pat) == SET) + { + if (!valid_replacement_for_asm_input_p_1 (SET_SRC (pat), src, dest)) + return false; + } + else if (GET_CODE (pat) == PARALLEL) + for (int i = 0, len = XVECLEN (pat, 0); i < len; ++i) + { + rtx asmops = XVECEXP (pat, 0, i); + if (GET_CODE (asmops) == SET) + asmops = SET_SRC (asmops); + if (GET_CODE (asmops) == ASM_OPERANDS + && !valid_replacement_for_asm_input_p_1 (asmops, src, dest)) + return false; + } + else if (GET_CODE (pat) == ASM_OPERANDS) + { + if (!valid_replacement_for_asm_input_p_1 (pat, src, dest)) + return false; + } + else + gcc_unreachable (); + } + } + return true; +} + /* Search forward to see if the source register of a copy insn dies before either it or the destination register is modified, but don't scan past the end of the basic block. If so, we can replace the @@ -2162,7 +2243,8 @@ decrease_live_ranges_number (void) auto-inc memory reference, so we must disallow this optimization on them. */ || sregno == STACK_POINTER_REGNUM - || dregno == STACK_POINTER_REGNUM) + || dregno == STACK_POINTER_REGNUM + || !valid_replacement_for_asm_input_p (src, dest)) continue; dest_death = NULL_RTX; |