motiejus/zig
1
Fork 0
Code Releases Activity

make f80 less hacky; lower as u80 on non-x86

Browse Source 
Get rid of `std.math.F80Repr`. Instead of trying to match the memory
layout of f80, we treat it as a value, same as the other floating point
types. The functions `make_f80` and `break_f80` are introduced to
compose an f80 value out of its parts, and the inverse operation.

stage2 LLVM backend: fix pointer to zero length array tripping LLVM
assertion. It now checks for when the element type is a zero-bit type
and lowers such thing the same way that pointers to other zero-bit types
are lowered.

Both stage1 and stage2 LLVM backends are adjusted so that f80 is lowered
as x86_fp80 on x86_64 and i386 architectures, and identical to a u80 on
others. LLVM constants are lowered in a less hacky way now that #10860
is fixed, by using the expression `(exp << 64) | fraction` using llvm
constants.

Sema is improved to handle c_longdouble by recursively handling it
correctly for whatever the float bit width is. In both stage1 and
stage2.
This commit is contained in:
Andrew Kelley
2022-02-10 22:06:43 -07:00
committed by Jakub Konka
parent 1c23321d03
commit a024aff932
10 changed files with 200 additions and 110 deletions
Download Patch File Download Diff File Expand all files Collapse all files

68
src/stage1/codegen.cpp
View File

@@ -8195,17 +8195,15 @@ static LLVMValueRef gen_const_val(CodeGen *g, ZigValue *const_val, const char *n
case 64:
return LLVMConstReal(get_llvm_type(g, type_entry), const_val->data.x_f64);
case 80: {
uint64_t buf[2];
memcpy(&buf, &const_val->data.x_f80, 16);
#if ZIG_BYTE_ORDER == ZIG_BIG_ENDIAN
uint64_t tmp = buf[0];
buf[0] = buf[1];
buf[1] = tmp;
#endif
LLVMValueRef as_i128 = LLVMConstIntOfArbitraryPrecision(LLVMInt128Type(), 2, buf);
if (!target_has_f80(g->zig_target)) return as_i128;
LLVMValueRef as_int = LLVMConstTrunc(as_i128, LLVMIntType(80));
return LLVMConstBitCast(as_int, get_llvm_type(g, type_entry));
LLVMTypeRef llvm_i80 = LLVMIntType(80);
LLVMValueRef x = LLVMConstInt(llvm_i80, const_val->data.x_f80.signExp, false);
x = LLVMConstShl(x, LLVMConstInt(llvm_i80, 64, false));
x = LLVMConstOr(x, LLVMConstInt(llvm_i80, const_val->data.x_f80.signif, false));
if (target_has_f80(g->zig_target)) {
return LLVMConstBitCast(x, LLVMX86FP80Type());
} else {
return x;
}
}
case 128:
{
@@ -9429,32 +9427,36 @@ static void define_builtin_types(CodeGen *g) {
{
ZigType *entry = new_type_table_entry(ZigTypeIdFloat);
unsigned u64_alignment = LLVMABIAlignmentOfType(g->target_data_ref, LLVMInt64Type());
entry->size_in_bits = 80;
if (u64_alignment >= 8) {
entry->size_in_bits = 128;
entry->abi_size = 16;
entry->abi_align = 16;
} else if (u64_alignment >= 4) {
entry->size_in_bits = 96;
entry->abi_size = 12;
entry->abi_align = 4;
} else {
entry->size_in_bits = 80;
entry->abi_size = 10;
entry->abi_align = 2;
}
if (target_has_f80(g->zig_target)) {
entry->llvm_type = LLVMX86FP80Type();
} else {
// We use an int here instead of x86_fp80 because on targets such as arm,
// LLVM will give "ERROR: Cannot select" for any instructions involving
// the x86_fp80 type.
entry->llvm_type = get_int_type(g, false, entry->size_in_bits)->llvm_type;
}
buf_init_from_str(&entry->name, "f80");
entry->data.floating.bit_count = 80;
switch (g->zig_target->arch) {
case ZigLLVM_x86_64:
entry->llvm_type = LLVMX86FP80Type();
entry->abi_size = 16;
entry->abi_align = 16;
break;
case ZigLLVM_x86:
entry->llvm_type = LLVMX86FP80Type();
entry->abi_size = 12;
entry->abi_align = 4;
break;
default: {
// We use an int here instead of x86_fp80 because on targets such as arm,
// LLVM will give "ERROR: Cannot select" for any instructions involving
// the x86_fp80 type.
ZigType *u80_ty = get_int_type(g, false, 80);
assert(!target_has_f80(g->zig_target));
assert(u80_ty->size_in_bits == entry->size_in_bits);
entry->llvm_type = get_llvm_type(g, u80_ty);
entry->abi_size = u80_ty->abi_size;
entry->abi_align = u80_ty->abi_align;
break;
}
}
entry->llvm_di_type = ZigLLVMCreateDebugBasicType(g->dbuilder, buf_ptr(&entry->name),
entry->size_in_bits, ZigLLVMEncoding_DW_ATE_unsigned());