fix NaN comparing equal to itself

This was broken both in comptime code and in runtime code.

closes #1174
master
Andrew Kelley 2019-04-04 22:07:15 -04:00
parent 8e6ff8d615
commit 1dc6751721
No known key found for this signature in database
GPG Key ID: 7C5F548F728501A9
6 changed files with 54 additions and 1 deletions

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@ -302,6 +302,7 @@ set(EMBEDDED_SOFTFLOAT_SOURCES
"${CMAKE_SOURCE_DIR}/deps/SoftFloat-3e/source/f16_add.c"
"${CMAKE_SOURCE_DIR}/deps/SoftFloat-3e/source/f16_div.c"
"${CMAKE_SOURCE_DIR}/deps/SoftFloat-3e/source/f16_eq.c"
"${CMAKE_SOURCE_DIR}/deps/SoftFloat-3e/source/f16_isSignalingNaN.c"
"${CMAKE_SOURCE_DIR}/deps/SoftFloat-3e/source/f16_lt.c"
"${CMAKE_SOURCE_DIR}/deps/SoftFloat-3e/source/f16_mul.c"
"${CMAKE_SOURCE_DIR}/deps/SoftFloat-3e/source/f16_rem.c"

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@ -190,3 +190,7 @@ bool bigfloat_has_fraction(const BigFloat *bigfloat) {
void bigfloat_sqrt(BigFloat *dest, const BigFloat *op) {
f128M_sqrt(&op->value, &dest->value);
}
bool bigfloat_is_nan(const BigFloat *op) {
return f128M_isSignalingNaN(&op->value);
}

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@ -48,6 +48,7 @@ void bigfloat_sqrt(BigFloat *dest, const BigFloat *op);
void bigfloat_append_buf(Buf *buf, const BigFloat *op);
Cmp bigfloat_cmp(const BigFloat *op1, const BigFloat *op2);
bool bigfloat_is_nan(const BigFloat *op);
// convenience functions
Cmp bigfloat_cmp_zero(const BigFloat *bigfloat);

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@ -1852,7 +1852,7 @@ static LLVMRealPredicate cmp_op_to_real_predicate(IrBinOp cmp_op) {
case IrBinOpCmpEq:
return LLVMRealOEQ;
case IrBinOpCmpNotEq:
return LLVMRealONE;
return LLVMRealUNE;
case IrBinOpCmpLessThan:
return LLVMRealOLT;
case IrBinOpCmpGreaterThan:

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@ -17,6 +17,7 @@
#include "util.hpp"
#include <errno.h>
#include <math.h>
struct IrExecContext {
ZigList<ConstExprValue *> mem_slot_list;
@ -8242,6 +8243,27 @@ static void float_init_float(ConstExprValue *dest_val, ConstExprValue *src_val)
}
}
static bool float_is_nan(ConstExprValue *op) {
if (op->type->id == ZigTypeIdComptimeFloat) {
return bigfloat_is_nan(&op->data.x_bigfloat);
} else if (op->type->id == ZigTypeIdFloat) {
switch (op->type->data.floating.bit_count) {
case 16:
return f16_isSignalingNaN(op->data.x_f16);
case 32:
return isnan(op->data.x_f32);
case 64:
return isnan(op->data.x_f64);
case 128:
return f128M_isSignalingNaN(&op->data.x_f128);
default:
zig_unreachable();
}
} else {
zig_unreachable();
}
}
static Cmp float_cmp(ConstExprValue *op1, ConstExprValue *op2) {
assert(op1->type == op2->type);
if (op1->type->id == ZigTypeIdComptimeFloat) {
@ -12378,6 +12400,9 @@ static IrInstruction *ir_analyze_bin_op_cmp(IrAnalyze *ira, IrInstructionBinOp *
return ira->codegen->invalid_instruction;
if (resolved_type->id == ZigTypeIdComptimeFloat || resolved_type->id == ZigTypeIdFloat) {
if (float_is_nan(op1_val) || float_is_nan(op2_val)) {
return ir_const_bool(ira, &bin_op_instruction->base, op_id == IrBinOpCmpNotEq);
}
Cmp cmp_result = float_cmp(op1_val, op2_val);
bool answer = resolve_cmp_op_id(op_id, cmp_result);
return ir_const_bool(ira, &bin_op_instruction->base, answer);

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@ -610,3 +610,25 @@ test "vector integer addition" {
S.doTheTest();
comptime S.doTheTest();
}
test "NaN comparison" {
testNanEqNan(f16);
testNanEqNan(f32);
testNanEqNan(f64);
testNanEqNan(f128);
comptime testNanEqNan(f16);
comptime testNanEqNan(f32);
comptime testNanEqNan(f64);
comptime testNanEqNan(f128);
}
fn testNanEqNan(comptime F: type) void {
var nan1 = std.math.nan(F);
var nan2 = std.math.nan(F);
expect(nan1 != nan2);
expect(!(nan1 == nan2));
expect(!(nan1 > nan2));
expect(!(nan1 >= nan2));
expect(!(nan1 < nan2));
expect(!(nan1 <= nan2));
}