diff options
Diffstat (limited to 'src/ir.cpp')
| -rw-r--r-- | src/ir.cpp | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/src/ir.cpp b/src/ir.cpp index b6a73638e3..67b5157c97 100644 --- a/src/ir.cpp +++ b/src/ir.cpp @@ -12932,7 +12932,52 @@ static bool optional_value_is_null(ConstExprValue *val) { } } +// Returns ErrorNotLazy when the value cannot be determined +static Error lazy_cmp_zero(AstNode *source_node, ConstExprValue *val, Cmp *result) { + Error err; + + switch (val->special) { + case ConstValSpecialRuntime: + case ConstValSpecialUndef: + return ErrorNotLazy; + case ConstValSpecialStatic: + switch (val->type->id) { + case ZigTypeIdComptimeInt: + case ZigTypeIdInt: + *result = bigint_cmp_zero(&val->data.x_bigint); + return ErrorNone; + default: + return ErrorNotLazy; + } + case ConstValSpecialLazy: + switch (val->data.x_lazy->id) { + case LazyValueIdInvalid: + zig_unreachable(); + case LazyValueIdAlignOf: + *result = CmpGT; + return ErrorNone; + case LazyValueIdSizeOf: { + LazyValueSizeOf *lazy_size_of = reinterpret_cast<LazyValueSizeOf *>(val->data.x_lazy); + IrAnalyze *ira = lazy_size_of->ira; + bool is_zero_bits; + if ((err = type_val_resolve_zero_bits(ira->codegen, &lazy_size_of->target_type->value, + nullptr, nullptr, &is_zero_bits))) + { + return err; + } + *result = is_zero_bits ? CmpEQ : CmpGT; + return ErrorNone; + } + default: + return ErrorNotLazy; + } + } + zig_unreachable(); +} + static IrInstruction *ir_analyze_bin_op_cmp(IrAnalyze *ira, IrInstructionBinOp *bin_op_instruction) { + Error err; + IrInstruction *op1 = bin_op_instruction->op1->child; if (type_is_invalid(op1->value.type)) return ira->codegen->invalid_instruction; @@ -13182,6 +13227,50 @@ static IrInstruction *ir_analyze_bin_op_cmp(IrAnalyze *ira, IrInstructionBinOp * } if (one_possible_value || (instr_is_comptime(casted_op1) && instr_is_comptime(casted_op2))) { + { + // Before resolving the values, we special case comparisons against zero. These can often be done + // without resolving lazy values, preventing potential dependency loops. + Cmp op1_cmp_zero; + if ((err = lazy_cmp_zero(bin_op_instruction->base.source_node, &casted_op1->value, &op1_cmp_zero))) { + if (err == ErrorNotLazy) goto never_mind_just_calculate_it_normally; + return ira->codegen->invalid_instruction; + } + Cmp op2_cmp_zero; + if ((err = lazy_cmp_zero(bin_op_instruction->base.source_node, &casted_op2->value, &op2_cmp_zero))) { + if (err == ErrorNotLazy) goto never_mind_just_calculate_it_normally; + return ira->codegen->invalid_instruction; + } + bool can_cmp_zero = false; + Cmp cmp_result; + if (op1_cmp_zero == CmpEQ && op2_cmp_zero == CmpEQ) { + can_cmp_zero = true; + cmp_result = CmpEQ; + } else if (op1_cmp_zero == CmpGT && op2_cmp_zero == CmpEQ) { + can_cmp_zero = true; + cmp_result = CmpGT; + } else if (op1_cmp_zero == CmpEQ && op2_cmp_zero == CmpGT) { + can_cmp_zero = true; + cmp_result = CmpLT; + } else if (op1_cmp_zero == CmpLT && op2_cmp_zero == CmpEQ) { + can_cmp_zero = true; + cmp_result = CmpLT; + } else if (op1_cmp_zero == CmpEQ && op2_cmp_zero == CmpLT) { + can_cmp_zero = true; + cmp_result = CmpGT; + } else if (op1_cmp_zero == CmpLT && op2_cmp_zero == CmpGT) { + can_cmp_zero = true; + cmp_result = CmpLT; + } else if (op1_cmp_zero == CmpGT && op2_cmp_zero == CmpLT) { + can_cmp_zero = true; + cmp_result = CmpGT; + } + if (can_cmp_zero) { + bool answer = resolve_cmp_op_id(op_id, cmp_result); + return ir_const_bool(ira, &bin_op_instruction->base, answer); + } + } +never_mind_just_calculate_it_normally: + ConstExprValue *op1_val = one_possible_value ? &casted_op1->value : ir_resolve_const(ira, casted_op1, UndefBad); if (op1_val == nullptr) return ira->codegen->invalid_instruction; |