From 8df69c95c3163562b6caf6c55651363c17c3f478 Mon Sep 17 00:00:00 2001 From: gingerBill Date: Sun, 10 Aug 2025 18:29:08 +0100 Subject: [PATCH] Add `-integer-division-by-zero:all-bits` --- src/build_settings.cpp | 19 ++++++++++++++----- src/check_expr.cpp | 31 +++++++++++++++++++++++++------ src/llvm_backend_expr.cpp | 19 +++++++++++++++++++ src/main.cpp | 1 + 4 files changed, 59 insertions(+), 11 deletions(-) diff --git a/src/build_settings.cpp b/src/build_settings.cpp index fad4bedaa..4bee0ad4e 100644 --- a/src/build_settings.cpp +++ b/src/build_settings.cpp @@ -353,14 +353,18 @@ enum OptInFeatureFlags : u64 { OptInFeatureFlag_NONE = 0, OptInFeatureFlag_DynamicLiterals = 1u<<0, - OptInFeatureFlag_IntegerDivisionByZero_Trap = 1u<<1, - OptInFeatureFlag_IntegerDivisionByZero_Zero = 1u<<2, - OptInFeatureFlag_IntegerDivisionByZero_Self = 1u<<3, + OptInFeatureFlag_GlobalContext = 1u<<1, - OptInFeatureFlag_GlobalContext = 1u<<4, + OptInFeatureFlag_IntegerDivisionByZero_Trap = 1u<<2, + OptInFeatureFlag_IntegerDivisionByZero_Zero = 1u<<3, + OptInFeatureFlag_IntegerDivisionByZero_Self = 1u<<4, + OptInFeatureFlag_IntegerDivisionByZero_AllBits = 1u<<5, - OptInFeatureFlag_IntegerDivisionByZero_ALL = OptInFeatureFlag_IntegerDivisionByZero_Trap|OptInFeatureFlag_IntegerDivisionByZero_Zero|OptInFeatureFlag_IntegerDivisionByZero_Self, + OptInFeatureFlag_IntegerDivisionByZero_ALL = OptInFeatureFlag_IntegerDivisionByZero_Trap| + OptInFeatureFlag_IntegerDivisionByZero_Zero| + OptInFeatureFlag_IntegerDivisionByZero_Self| + OptInFeatureFlag_IntegerDivisionByZero_AllBits, }; @@ -377,6 +381,10 @@ u64 get_feature_flag_from_name(String const &name) { if (name == "integer-division-by-zero:self") { return OptInFeatureFlag_IntegerDivisionByZero_Self; } + if (name == "integer-division-by-zero:all-bits") { + return OptInFeatureFlag_IntegerDivisionByZero_AllBits; + } + if (name == "global-context") { return OptInFeatureFlag_GlobalContext; @@ -431,6 +439,7 @@ enum IntegerDivisionByZeroKind : u8 { IntegerDivisionByZero_Trap, IntegerDivisionByZero_Zero, IntegerDivisionByZero_Self, + IntegerDivisionByZero_AllBits, }; // This stores the information for the specify architecture of this build diff --git a/src/check_expr.cpp b/src/check_expr.cpp index e0b6408e3..7020b4f4b 100644 --- a/src/check_expr.cpp +++ b/src/check_expr.cpp @@ -4377,12 +4377,23 @@ gb_internal void check_binary_expr(CheckerContext *c, Operand *x, Ast *node, Typ b.kind == ExactValue_Integer && big_int_is_zero(&b.value_integer) && (op.kind == Token_QuoEq || op.kind == Token_Mod || op.kind == Token_ModMod)) { if (op.kind == Token_QuoEq) { - if (zero_behaviour == IntegerDivisionByZero_Zero) { + switch (zero_behaviour) { + case IntegerDivisionByZero_Zero: // x/0 == 0 x->value = b; - } else { + break; + case IntegerDivisionByZero_Self: // x/0 == x x->value = a; + break; + case IntegerDivisionByZero_AllBits: + // x/0 == 0b111...111 + if (is_type_untyped(x->type)) { + x->value = exact_value_i64(-1); + } else { + x->value = exact_unary_operator_value(Token_Xor, b, cast(i32)(8*type_size_of(x->type)), is_type_unsigned(x->type)); + } + break; } } else { /* @@ -4391,16 +4402,21 @@ gb_internal void check_binary_expr(CheckerContext *c, Operand *x, Ast *node, Typ truncated: r = a - b*trunc(a/b) floored: r = a - b*floor(a/b) - IFF a/0 == 0, then (a%0 == a) or (a%%0 == a) - IFF a/0 == a, then (a%0 == 0) or (a%%0 == 0) + IFF a/0 == 0, then (a%0 == a) or (a%%0 == a) + IFF a/0 == a, then (a%0 == 0) or (a%%0 == 0) + IFF a/0 == 0b111..., then (a%0 == a) or (a%%0 == a) */ - if (zero_behaviour == IntegerDivisionByZero_Zero) { + switch (zero_behaviour) { + case IntegerDivisionByZero_Zero: + case IntegerDivisionByZero_AllBits: // x%0 == x x->value = a; - } else { + break; + case IntegerDivisionByZero_Self: // x%0 == 0 x->value = b; + break; } } } else { @@ -9670,6 +9686,9 @@ gb_internal IntegerDivisionByZeroKind check_for_integer_division_by_zero(Checker if ((flags & OptInFeatureFlag_IntegerDivisionByZero_Self) != 0) { return IntegerDivisionByZero_Self; } + if ((flags & OptInFeatureFlag_IntegerDivisionByZero_AllBits) != 0) { + return IntegerDivisionByZero_AllBits; + } return build_context.integer_division_by_zero_behaviour; } diff --git a/src/llvm_backend_expr.cpp b/src/llvm_backend_expr.cpp index dbbc6268a..ebc3ec158 100644 --- a/src/llvm_backend_expr.cpp +++ b/src/llvm_backend_expr.cpp @@ -305,6 +305,9 @@ gb_internal IntegerDivisionByZeroKind lb_check_for_integer_division_by_zero_beha if (flags & OptInFeatureFlag_IntegerDivisionByZero_Self) { return IntegerDivisionByZero_Self; } + if (flags & OptInFeatureFlag_IntegerDivisionByZero_AllBits) { + return IntegerDivisionByZero_AllBits; + } } return build_context.integer_division_by_zero_behaviour; } @@ -1140,6 +1143,7 @@ gb_internal LLVMValueRef lb_integer_division(lbProcedure *p, LLVMValueRef lhs, L GB_ASSERT(LLVMTypeOf(lhs) == type); LLVMValueRef zero = LLVMConstNull(type); + LLVMValueRef all_bits = LLVMConstNot(zero); auto behaviour = lb_check_for_integer_division_by_zero_behaviour(p); auto *call = is_signed ? LLVMBuildSDiv : LLVMBuildUDiv; @@ -1151,6 +1155,9 @@ gb_internal LLVMValueRef lb_integer_division(lbProcedure *p, LLVMValueRef lhs, L return lhs; case IntegerDivisionByZero_Zero: return zero; + case IntegerDivisionByZero_AllBits: + // return all_bits; + break; } } else { if (!is_signed && lb_sizeof(type) <= 8) { @@ -1198,6 +1205,9 @@ gb_internal LLVMValueRef lb_integer_division(lbProcedure *p, LLVMValueRef lhs, L case IntegerDivisionByZero_Self: incoming_values[1] = lhs; break; + case IntegerDivisionByZero_AllBits: + incoming_values[1] = all_bits; + break; } lb_emit_jump(p, done_block); @@ -1211,6 +1221,7 @@ gb_internal LLVMValueRef lb_integer_division(lbProcedure *p, LLVMValueRef lhs, L res = incoming_values[0]; break; case IntegerDivisionByZero_Zero: + case IntegerDivisionByZero_AllBits: res = LLVMBuildPhi(p->builder, type, ""); GB_ASSERT(p->curr_block->preds.count >= 2); @@ -1229,6 +1240,7 @@ gb_internal LLVMValueRef lb_integer_division_intrinsics(lbProcedure *p, LLVMValu GB_ASSERT(LLVMTypeOf(lhs) == type); LLVMValueRef zero = LLVMConstNull(type); + LLVMValueRef all_bits = LLVMConstNot(zero); auto behaviour = lb_check_for_integer_division_by_zero_behaviour(p); auto const do_op = [&]() -> LLVMValueRef { @@ -1285,6 +1297,9 @@ gb_internal LLVMValueRef lb_integer_division_intrinsics(lbProcedure *p, LLVMValu case IntegerDivisionByZero_Self: incoming_values[1] = lhs; break; + case IntegerDivisionByZero_AllBits: + incoming_values[1] = all_bits; + break; } lb_emit_jump(p, done_block); @@ -1298,6 +1313,7 @@ gb_internal LLVMValueRef lb_integer_division_intrinsics(lbProcedure *p, LLVMValu res = incoming_values[0]; break; case IntegerDivisionByZero_Zero: + case IntegerDivisionByZero_AllBits: res = LLVMBuildPhi(p->builder, type, ""); GB_ASSERT(p->curr_block->preds.count >= 2); @@ -1344,6 +1360,7 @@ gb_internal LLVMValueRef lb_integer_modulo(lbProcedure *p, LLVMValueRef lhs, LLV case IntegerDivisionByZero_Self: return zero; case IntegerDivisionByZero_Zero: + case IntegerDivisionByZero_AllBits: return lhs; } } else { @@ -1386,6 +1403,7 @@ gb_internal LLVMValueRef lb_integer_modulo(lbProcedure *p, LLVMValueRef lhs, LLV LLVMBuildUnreachable(p->builder); break; case IntegerDivisionByZero_Zero: + case IntegerDivisionByZero_AllBits: incoming_values[1] = lhs; break; case IntegerDivisionByZero_Self: @@ -1404,6 +1422,7 @@ gb_internal LLVMValueRef lb_integer_modulo(lbProcedure *p, LLVMValueRef lhs, LLV res = incoming_values[0]; break; case IntegerDivisionByZero_Zero: + case IntegerDivisionByZero_AllBits: res = LLVMBuildPhi(p->builder, type, ""); GB_ASSERT(p->curr_block->preds.count >= 2); diff --git a/src/main.cpp b/src/main.cpp index 06b9cab94..db4dee080 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -2589,6 +2589,7 @@ gb_internal int print_show_help(String const arg0, String command, String option print_usage_line(3, "-integer-division-by-zero:trap Trap on division/modulo/remainder by zero"); print_usage_line(3, "-integer-division-by-zero:zero x/0 == 0 and x%%0 == x and x%%%%0 == x"); print_usage_line(3, "-integer-division-by-zero:self x/0 == x and x%%0 == 0 and x%%%%0 == 0"); + print_usage_line(3, "-integer-division-by-zero:all-bits x/0 == ~T(0) and x%%0 == x and x%%%%0 == x"); } }