From f6cd68386d76e4a9a489187c47f218b59e1734f3 Mon Sep 17 00:00:00 2001
From: vegecode <39607947+vegecode@users.noreply.github.com>
Date: Wed, 2 Jan 2019 15:47:47 -0600
Subject: [PATCH] @bitreverse intrinsic, part of #767 (#1865)
* bitreverse - give bswap behavior
* bitreverse, comptime_ints, negative values still not working?
* bitreverse working for negative comptime ints
* Finished bitreverse test cases
* Undo exporting a bigint function. @bitreverse test name includes ampersand
* added docs entry for @bitreverse
---
doc/langref.html.in | 12 +++++
src/all_types.hpp | 13 ++++++
src/analyze.cpp | 4 ++
src/bigint.cpp | 1 +
src/codegen.cpp | 16 +++++++
src/ir.cpp | 98 ++++++++++++++++++++++++++++++++++++++-
src/ir_print.cpp | 15 ++++++
test/behavior.zig | 1 +
test/cases/bitreverse.zig | 81 ++++++++++++++++++++++++++++++++
9 files changed, 240 insertions(+), 1 deletion(-)
create mode 100644 test/cases/bitreverse.zig
diff --git a/doc/langref.html.in b/doc/langref.html.in
index 2a2b4003fb..6e03d3ec6d 100644
--- a/doc/langref.html.in
+++ b/doc/langref.html.in
@@ -5316,6 +5316,18 @@ comptime {
{#header_close#}
+ {#header_open|@bitreverse#}
+ {#syntax#}@bitreverse(comptime T: type, value: T) T{#endsyntax#}
+ {#syntax#}T{#endsyntax#} accepts any integer type.
+
+ Reverses the bitpattern of an integer value, including the sign bit if applicable.
+
+
+ For example 0b10110110 ({#syntax#}u8 = 182{#endsyntax#}, {#syntax#}i8 = -74{#endsyntax#})
+ becomes 0b01101101 ({#syntax#}u8 = 109{#endsyntax#}, {#syntax#}i8 = 109{#endsyntax#}).
+
+ {#header_close#}
+
{#header_open|@byteOffsetOf#}
{#syntax#}@byteOffsetOf(comptime T: type, comptime field_name: [] const u8) comptime_int{#endsyntax#}
diff --git a/src/all_types.hpp b/src/all_types.hpp
index 2b55f8ee2e..df318729f5 100644
--- a/src/all_types.hpp
+++ b/src/all_types.hpp
@@ -1415,6 +1415,7 @@ enum BuiltinFnId {
BuiltinFnIdAtomicRmw,
BuiltinFnIdAtomicLoad,
BuiltinFnIdBswap,
+ BuiltinFnIdBitReverse,
};
struct BuiltinFnEntry {
@@ -1488,6 +1489,7 @@ enum ZigLLVMFnId {
ZigLLVMFnIdCeil,
ZigLLVMFnIdSqrt,
ZigLLVMFnIdBswap,
+ ZigLLVMFnIdBitReverse,
};
enum AddSubMul {
@@ -1520,6 +1522,9 @@ struct ZigLLVMFnKey {
struct {
uint32_t bit_count;
} bswap;
+ struct {
+ uint32_t bit_count;
+ } bit_reverse;
} data;
};
@@ -2162,6 +2167,7 @@ enum IrInstructionId {
IrInstructionIdMarkErrRetTracePtr,
IrInstructionIdSqrt,
IrInstructionIdBswap,
+ IrInstructionIdBitReverse,
IrInstructionIdErrSetCast,
IrInstructionIdToBytes,
IrInstructionIdFromBytes,
@@ -3262,6 +3268,13 @@ struct IrInstructionBswap {
IrInstruction *op;
};
+struct IrInstructionBitReverse {
+ IrInstruction base;
+
+ IrInstruction *type;
+ IrInstruction *op;
+};
+
static const size_t slice_ptr_index = 0;
static const size_t slice_len_index = 1;
diff --git a/src/analyze.cpp b/src/analyze.cpp
index 0f2b8e48cc..b9794114a0 100644
--- a/src/analyze.cpp
+++ b/src/analyze.cpp
@@ -6121,6 +6121,8 @@ uint32_t zig_llvm_fn_key_hash(ZigLLVMFnKey x) {
return (uint32_t)(x.data.floating.bit_count) * (uint32_t)2225366385;
case ZigLLVMFnIdBswap:
return (uint32_t)(x.data.bswap.bit_count) * (uint32_t)3661994335;
+ case ZigLLVMFnIdBitReverse:
+ return (uint32_t)(x.data.bit_reverse.bit_count) * (uint32_t)2621398431;
case ZigLLVMFnIdOverflowArithmetic:
return ((uint32_t)(x.data.overflow_arithmetic.bit_count) * 87135777) +
((uint32_t)(x.data.overflow_arithmetic.add_sub_mul) * 31640542) +
@@ -6141,6 +6143,8 @@ bool zig_llvm_fn_key_eql(ZigLLVMFnKey a, ZigLLVMFnKey b) {
return a.data.pop_count.bit_count == b.data.pop_count.bit_count;
case ZigLLVMFnIdBswap:
return a.data.bswap.bit_count == b.data.bswap.bit_count;
+ case ZigLLVMFnIdBitReverse:
+ return a.data.bit_reverse.bit_count == b.data.bit_reverse.bit_count;
case ZigLLVMFnIdFloor:
case ZigLLVMFnIdCeil:
case ZigLLVMFnIdSqrt:
diff --git a/src/bigint.cpp b/src/bigint.cpp
index 8a8d028e82..7299f2379c 100644
--- a/src/bigint.cpp
+++ b/src/bigint.cpp
@@ -1722,3 +1722,4 @@ void bigint_incr(BigInt *x) {
bigint_add(x, ©, &one);
}
+
diff --git a/src/codegen.cpp b/src/codegen.cpp
index 6a0596f62f..db8a5f7bb2 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -3789,6 +3789,11 @@ static LLVMValueRef get_int_builtin_fn(CodeGen *g, ZigType *int_type, BuiltinFnI
n_args = 1;
key.id = ZigLLVMFnIdBswap;
key.data.bswap.bit_count = (uint32_t)int_type->data.integral.bit_count;
+ } else if (fn_id == BuiltinFnIdBitReverse) {
+ fn_name = "bitreverse";
+ n_args = 1;
+ key.id = ZigLLVMFnIdBitReverse;
+ key.data.bit_reverse.bit_count = (uint32_t)int_type->data.integral.bit_count;
} else {
zig_unreachable();
}
@@ -5096,6 +5101,14 @@ static LLVMValueRef ir_render_bswap(CodeGen *g, IrExecutable *executable, IrInst
return LLVMBuildTrunc(g->builder, shifted, int_type->type_ref, "");
}
+static LLVMValueRef ir_render_bit_reverse(CodeGen *g, IrExecutable *executable, IrInstructionBitReverse *instruction) {
+ LLVMValueRef op = ir_llvm_value(g, instruction->op);
+ ZigType *int_type = instruction->base.value.type;
+ assert(int_type->id == ZigTypeIdInt);
+ LLVMValueRef fn_val = get_int_builtin_fn(g, instruction->base.value.type, BuiltinFnIdBitReverse);
+ return LLVMBuildCall(g->builder, fn_val, &op, 1, "");
+}
+
static void set_debug_location(CodeGen *g, IrInstruction *instruction) {
AstNode *source_node = instruction->source_node;
Scope *scope = instruction->scope;
@@ -5335,6 +5348,8 @@ static LLVMValueRef ir_render_instruction(CodeGen *g, IrExecutable *executable,
return ir_render_sqrt(g, executable, (IrInstructionSqrt *)instruction);
case IrInstructionIdBswap:
return ir_render_bswap(g, executable, (IrInstructionBswap *)instruction);
+ case IrInstructionIdBitReverse:
+ return ir_render_bit_reverse(g, executable, (IrInstructionBitReverse *)instruction);
}
zig_unreachable();
}
@@ -6758,6 +6773,7 @@ static void define_builtin_fns(CodeGen *g) {
create_builtin_fn(g, BuiltinFnIdFromBytes, "bytesToSlice", 2);
create_builtin_fn(g, BuiltinFnIdThis, "This", 0);
create_builtin_fn(g, BuiltinFnIdBswap, "bswap", 2);
+ create_builtin_fn(g, BuiltinFnIdBitReverse, "bitreverse", 2);
}
static const char *bool_to_str(bool b) {
diff --git a/src/ir.cpp b/src/ir.cpp
index b1429ae8ac..dac5403550 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -861,6 +861,10 @@ static constexpr IrInstructionId ir_instruction_id(IrInstructionBswap *) {
return IrInstructionIdBswap;
}
+static constexpr IrInstructionId ir_instruction_id(IrInstructionBitReverse *) {
+ return IrInstructionIdBitReverse;
+}
+
static constexpr IrInstructionId ir_instruction_id(IrInstructionCheckRuntimeScope *) {
return IrInstructionIdCheckRuntimeScope;
}
@@ -2721,6 +2725,17 @@ static IrInstruction *ir_build_bswap(IrBuilder *irb, Scope *scope, AstNode *sour
return &instruction->base;
}
+static IrInstruction *ir_build_bit_reverse(IrBuilder *irb, Scope *scope, AstNode *source_node, IrInstruction *type, IrInstruction *op) {
+ IrInstructionBitReverse *instruction = ir_build_instruction(irb, scope, source_node);
+ instruction->type = type;
+ instruction->op = op;
+
+ if (type != nullptr) ir_ref_instruction(type, irb->current_basic_block);
+ ir_ref_instruction(op, irb->current_basic_block);
+
+ return &instruction->base;
+}
+
static IrInstruction *ir_build_check_runtime_scope(IrBuilder *irb, Scope *scope, AstNode *source_node, IrInstruction *scope_is_comptime, IrInstruction *is_comptime) {
IrInstructionCheckRuntimeScope *instruction = ir_build_instruction(irb, scope, source_node);
instruction->scope_is_comptime = scope_is_comptime;
@@ -3646,7 +3661,7 @@ static IrInstruction *ir_gen_builtin_fn_call(IrBuilder *irb, Scope *scope, AstNo
Buf *name = fn_ref_expr->data.symbol_expr.symbol;
auto entry = irb->codegen->builtin_fn_table.maybe_get(name);
- if (!entry) {
+ if (!entry) { // new built in not found
add_node_error(irb->codegen, node,
buf_sprintf("invalid builtin function: '%s'", buf_ptr(name)));
return irb->codegen->invalid_instruction;
@@ -4720,6 +4735,21 @@ static IrInstruction *ir_gen_builtin_fn_call(IrBuilder *irb, Scope *scope, AstNo
IrInstruction *result = ir_build_bswap(irb, scope, node, arg0_value, arg1_value);
return ir_lval_wrap(irb, scope, result, lval);
}
+ case BuiltinFnIdBitReverse:
+ {
+ AstNode *arg0_node = node->data.fn_call_expr.params.at(0);
+ IrInstruction *arg0_value = ir_gen_node(irb, arg0_node, scope);
+ if (arg0_value == irb->codegen->invalid_instruction)
+ return arg0_value;
+
+ AstNode *arg1_node = node->data.fn_call_expr.params.at(1);
+ IrInstruction *arg1_value = ir_gen_node(irb, arg1_node, scope);
+ if (arg1_value == irb->codegen->invalid_instruction)
+ return arg1_value;
+
+ IrInstruction *result = ir_build_bit_reverse(irb, scope, node, arg0_value, arg1_value);
+ return ir_lval_wrap(irb, scope, result, lval);
+ }
}
zig_unreachable();
}
@@ -21115,6 +21145,69 @@ static IrInstruction *ir_analyze_instruction_bswap(IrAnalyze *ira, IrInstruction
return result;
}
+static IrInstruction *ir_analyze_instruction_bit_reverse(IrAnalyze *ira, IrInstructionBitReverse *instruction) {
+ ZigType *int_type = ir_resolve_type(ira, instruction->type->child);
+ if (type_is_invalid(int_type))
+ return ira->codegen->invalid_instruction;
+
+ IrInstruction *op = instruction->op->child;
+ if (type_is_invalid(op->value.type))
+ return ira->codegen->invalid_instruction;
+
+ if (int_type->id != ZigTypeIdInt) {
+ ir_add_error(ira, instruction->type,
+ buf_sprintf("expected integer type, found '%s'", buf_ptr(&int_type->name)));
+ return ira->codegen->invalid_instruction;
+ }
+
+ IrInstruction *casted_op = ir_implicit_cast(ira, op, int_type);
+ if (type_is_invalid(casted_op->value.type))
+ return ira->codegen->invalid_instruction;
+
+ if (int_type->data.integral.bit_count == 0) {
+ IrInstruction *result = ir_const(ira, &instruction->base, int_type);
+ bigint_init_unsigned(&result->value.data.x_bigint, 0);
+ return result;
+ }
+
+ if (instr_is_comptime(casted_op)) {
+ ConstExprValue *val = ir_resolve_const(ira, casted_op, UndefBad);
+ if (!val)
+ return ira->codegen->invalid_instruction;
+
+ IrInstruction *result = ir_const(ira, &instruction->base, int_type);
+ size_t num_bits = int_type->data.integral.bit_count;
+ size_t buf_size = (num_bits + 7) / 8;
+ uint8_t *comptime_buf = allocate_nonzero(buf_size);
+ uint8_t *result_buf = allocate_nonzero(buf_size);
+ memset(comptime_buf,0,buf_size);
+ memset(result_buf,0,buf_size);
+
+ bigint_write_twos_complement(&val->data.x_bigint,comptime_buf,num_bits,ira->codegen->is_big_endian);
+
+ size_t bit_i = 0;
+ size_t bit_rev_i = num_bits - 1;
+ for (; bit_i < num_bits; bit_i++, bit_rev_i--) {
+ if (comptime_buf[bit_i / 8] & (1 << (bit_i % 8))) {
+ result_buf[bit_rev_i / 8] |= (1 << (bit_rev_i % 8));
+ }
+ }
+
+ bigint_read_twos_complement(&result->value.data.x_bigint,
+ result_buf,
+ int_type->data.integral.bit_count,
+ ira->codegen->is_big_endian,
+ int_type->data.integral.is_signed);
+
+ return result;
+ }
+
+ IrInstruction *result = ir_build_bit_reverse(&ira->new_irb, instruction->base.scope,
+ instruction->base.source_node, nullptr, casted_op);
+ result->value.type = int_type;
+ return result;
+}
+
static IrInstruction *ir_analyze_instruction_enum_to_int(IrAnalyze *ira, IrInstructionEnumToInt *instruction) {
Error err;
@@ -21453,6 +21546,8 @@ static IrInstruction *ir_analyze_instruction_nocast(IrAnalyze *ira, IrInstructio
return ir_analyze_instruction_sqrt(ira, (IrInstructionSqrt *)instruction);
case IrInstructionIdBswap:
return ir_analyze_instruction_bswap(ira, (IrInstructionBswap *)instruction);
+ case IrInstructionIdBitReverse:
+ return ir_analyze_instruction_bit_reverse(ira, (IrInstructionBitReverse *)instruction);
case IrInstructionIdIntToErr:
return ir_analyze_instruction_int_to_err(ira, (IrInstructionIntToErr *)instruction);
case IrInstructionIdErrToInt:
@@ -21675,6 +21770,7 @@ bool ir_has_side_effects(IrInstruction *instruction) {
case IrInstructionIdPromiseResultType:
case IrInstructionIdSqrt:
case IrInstructionIdBswap:
+ case IrInstructionIdBitReverse:
case IrInstructionIdAtomicLoad:
case IrInstructionIdIntCast:
case IrInstructionIdFloatCast:
diff --git a/src/ir_print.cpp b/src/ir_print.cpp
index e09b0073eb..b5099db86a 100644
--- a/src/ir_print.cpp
+++ b/src/ir_print.cpp
@@ -1335,6 +1335,18 @@ static void ir_print_bswap(IrPrint *irp, IrInstructionBswap *instruction) {
fprintf(irp->f, ")");
}
+static void ir_print_bit_reverse(IrPrint *irp, IrInstructionBitReverse *instruction) {
+ fprintf(irp->f, "@bitreverse(");
+ if (instruction->type != nullptr) {
+ ir_print_other_instruction(irp, instruction->type);
+ } else {
+ fprintf(irp->f, "null");
+ }
+ fprintf(irp->f, ",");
+ ir_print_other_instruction(irp, instruction->op);
+ fprintf(irp->f, ")");
+}
+
static void ir_print_instruction(IrPrint *irp, IrInstruction *instruction) {
ir_print_prefix(irp, instruction);
switch (instruction->id) {
@@ -1751,6 +1763,9 @@ static void ir_print_instruction(IrPrint *irp, IrInstruction *instruction) {
case IrInstructionIdBswap:
ir_print_bswap(irp, (IrInstructionBswap *)instruction);
break;
+ case IrInstructionIdBitReverse:
+ ir_print_bit_reverse(irp, (IrInstructionBitReverse *)instruction);
+ break;
case IrInstructionIdAtomicLoad:
ir_print_atomic_load(irp, (IrInstructionAtomicLoad *)instruction);
break;
diff --git a/test/behavior.zig b/test/behavior.zig
index 8090359772..10cd08dad7 100644
--- a/test/behavior.zig
+++ b/test/behavior.zig
@@ -9,6 +9,7 @@ comptime {
_ = @import("cases/bitcast.zig");
_ = @import("cases/bool.zig");
_ = @import("cases/bswap.zig");
+ _ = @import("cases/bitreverse.zig");
_ = @import("cases/bugs/1076.zig");
_ = @import("cases/bugs/1111.zig");
_ = @import("cases/bugs/1277.zig");
diff --git a/test/cases/bitreverse.zig b/test/cases/bitreverse.zig
new file mode 100644
index 0000000000..3721e68a94
--- /dev/null
+++ b/test/cases/bitreverse.zig
@@ -0,0 +1,81 @@
+const std = @import("std");
+const assert = std.debug.assert;
+const minInt = std.math.minInt;
+
+test "@bitreverse" {
+ comptime testBitReverse();
+ testBitReverse();
+}
+
+fn testBitReverse() void {
+ // using comptime_ints, unsigned
+ assert(@bitreverse(u0, 0) == 0);
+ assert(@bitreverse(u5, 0x12) == 0x9);
+ assert(@bitreverse(u8, 0x12) == 0x48);
+ assert(@bitreverse(u16, 0x1234) == 0x2c48);
+ assert(@bitreverse(u24, 0x123456) == 0x6a2c48);
+ assert(@bitreverse(u32, 0x12345678) == 0x1e6a2c48);
+ assert(@bitreverse(u40, 0x123456789a) == 0x591e6a2c48);
+ assert(@bitreverse(u48, 0x123456789abc) == 0x3d591e6a2c48);
+ assert(@bitreverse(u56, 0x123456789abcde) == 0x7b3d591e6a2c48);
+ assert(@bitreverse(u64, 0x123456789abcdef1) == 0x8f7b3d591e6a2c48);
+ assert(@bitreverse(u128, 0x123456789abcdef11121314151617181) == 0x818e868a828c84888f7b3d591e6a2c48);
+
+ // using runtime uints, unsigned
+ var num0: u0 = 0;
+ assert(@bitreverse(u0, num0) == 0);
+ var num5: u5 = 0x12;
+ assert(@bitreverse(u5, num5) == 0x9);
+ var num8: u8 = 0x12;
+ assert(@bitreverse(u8, num8) == 0x48);
+ var num16: u16 = 0x1234;
+ assert(@bitreverse(u16, num16) == 0x2c48);
+ var num24: u24 = 0x123456;
+ assert(@bitreverse(u24, num24) == 0x6a2c48);
+ var num32: u32 = 0x12345678;
+ assert(@bitreverse(u32, num32) == 0x1e6a2c48);
+ var num40: u40 = 0x123456789a;
+ assert(@bitreverse(u40, num40) == 0x591e6a2c48);
+ var num48: u48 = 0x123456789abc;
+ assert(@bitreverse(u48, num48) == 0x3d591e6a2c48);
+ var num56: u56 = 0x123456789abcde;
+ assert(@bitreverse(u56, num56) == 0x7b3d591e6a2c48);
+ var num64: u64 = 0x123456789abcdef1;
+ assert(@bitreverse(u64, num64) == 0x8f7b3d591e6a2c48);
+ var num128: u128 = 0x123456789abcdef11121314151617181;
+ assert(@bitreverse(u128, num128) == 0x818e868a828c84888f7b3d591e6a2c48);
+
+ // using comptime_ints, signed, positive
+ assert(@bitreverse(i0, 0) == 0);
+ assert(@bitreverse(i8, @bitCast(i8, u8(0x92))) == @bitCast(i8, u8( 0x49)));
+ assert(@bitreverse(i16, @bitCast(i16, u16(0x1234))) == @bitCast(i16, u16( 0x2c48)));
+ assert(@bitreverse(i24, @bitCast(i24, u24(0x123456))) == @bitCast(i24, u24( 0x6a2c48)));
+ assert(@bitreverse(i32, @bitCast(i32, u32(0x12345678))) == @bitCast(i32, u32( 0x1e6a2c48)));
+ assert(@bitreverse(i40, @bitCast(i40, u40(0x123456789a))) == @bitCast(i40, u40( 0x591e6a2c48)));
+ assert(@bitreverse(i48, @bitCast(i48, u48(0x123456789abc))) == @bitCast(i48, u48( 0x3d591e6a2c48)));
+ assert(@bitreverse(i56, @bitCast(i56, u56(0x123456789abcde))) == @bitCast(i56, u56( 0x7b3d591e6a2c48)));
+ assert(@bitreverse(i64, @bitCast(i64, u64(0x123456789abcdef1))) == @bitCast(i64,u64(0x8f7b3d591e6a2c48)));
+ assert(@bitreverse(i128, @bitCast(i128,u128(0x123456789abcdef11121314151617181))) == @bitCast(i128,u128(0x818e868a828c84888f7b3d591e6a2c48)));
+
+ // using comptime_ints, signed, negative. Compare to runtime ints returned from llvm.
+ var neg5: i5 = minInt(i5) + 1;
+ assert(@bitreverse(i5, minInt(i5) + 1) == @bitreverse(i5, neg5));
+ var neg8: i8 = -18;
+ assert(@bitreverse(i8, -18) == @bitreverse(i8, neg8));
+ var neg16: i16 = -32694;
+ assert(@bitreverse(i16, -32694) == @bitreverse(i16, neg16));
+ var neg24: i24 = -6773785;
+ assert(@bitreverse(i24, -6773785) == @bitreverse(i24, neg24));
+ var neg32: i32 = -16773785;
+ assert(@bitreverse(i32, -16773785) == @bitreverse(i32, neg32));
+ var neg40: i40 = minInt(i40) + 12345;
+ assert(@bitreverse(i40, minInt(i40) + 12345) == @bitreverse(i40, neg40));
+ var neg48: i48 = minInt(i48) + 12345;
+ assert(@bitreverse(i48, minInt(i48) + 12345) == @bitreverse(i48, neg48));
+ var neg56: i56 = minInt(i56) + 12345;
+ assert(@bitreverse(i56, minInt(i56) + 12345) == @bitreverse(i56, neg56));
+ var neg64: i64 = minInt(i64) + 12345;
+ assert(@bitreverse(i64, minInt(i64) + 12345) == @bitreverse(i64, neg64));
+ var neg128: i128 = minInt(i128) + 12345;
+ assert(@bitreverse(i128, minInt(i128) + 12345) == @bitreverse(i128, neg128));
+}