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+//===-- lib/fp_compare_impl.inc - Floating-point comparison -------*- C -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "fp_lib.h"
+
+// GCC uses long (at least for x86_64) as the return type of the comparison
+// functions. We need to ensure that the return value is sign-extended in the
+// same way as GCC expects (since otherwise GCC-generated __builtin_isinf
+// returns true for finite 128-bit floating-point numbers).
+#ifdef __aarch64__
+// AArch64 GCC overrides libgcc_cmp_return to use int instead of long.
+typedef int CMP_RESULT;
+#elif __SIZEOF_POINTER__ == 8 && __SIZEOF_LONG__ == 4
+// LLP64 ABIs use long long instead of long.
+typedef long long CMP_RESULT;
+#elif __AVR__
+// AVR uses a single byte for the return value.
+typedef char CMP_RESULT;
+#else
+// Otherwise the comparison functions return long.
+typedef long CMP_RESULT;
+#endif
+
+#if !defined(__clang__) && defined(__GNUC__)
+// GCC uses a special __libgcc_cmp_return__ mode to define the return type, so
+// check that we are ABI-compatible when compiling the builtins with GCC.
+typedef int GCC_CMP_RESULT __attribute__((__mode__(__libgcc_cmp_return__)));
+_Static_assert(sizeof(GCC_CMP_RESULT) == sizeof(CMP_RESULT),
+ "SOFTFP ABI not compatible with GCC");
+#endif
+
+enum {
+ LE_LESS = -1,
+ LE_EQUAL = 0,
+ LE_GREATER = 1,
+ LE_UNORDERED = 1,
+};
+
+static inline CMP_RESULT __leXf2__(fp_t a, fp_t b) {
+ const srep_t aInt = toRep(a);
+ const srep_t bInt = toRep(b);
+ const rep_t aAbs = aInt & absMask;
+ const rep_t bAbs = bInt & absMask;
+
+ // If either a or b is NaN, they are unordered.
+ if (aAbs > infRep || bAbs > infRep)
+ return LE_UNORDERED;
+
+ // If a and b are both zeros, they are equal.
+ if ((aAbs | bAbs) == 0)
+ return LE_EQUAL;
+
+ // If at least one of a and b is positive, we get the same result comparing
+ // a and b as signed integers as we would with a floating-point compare.
+ if ((aInt & bInt) >= 0) {
+ if (aInt < bInt)
+ return LE_LESS;
+ else if (aInt == bInt)
+ return LE_EQUAL;
+ else
+ return LE_GREATER;
+ } else {
+ // Otherwise, both are negative, so we need to flip the sense of the
+ // comparison to get the correct result. (This assumes a twos- or ones-
+ // complement integer representation; if integers are represented in a
+ // sign-magnitude representation, then this flip is incorrect).
+ if (aInt > bInt)
+ return LE_LESS;
+ else if (aInt == bInt)
+ return LE_EQUAL;
+ else
+ return LE_GREATER;
+ }
+}
+
+enum {
+ GE_LESS = -1,
+ GE_EQUAL = 0,
+ GE_GREATER = 1,
+ GE_UNORDERED = -1 // Note: different from LE_UNORDERED
+};
+
+static inline CMP_RESULT __geXf2__(fp_t a, fp_t b) {
+ const srep_t aInt = toRep(a);
+ const srep_t bInt = toRep(b);
+ const rep_t aAbs = aInt & absMask;
+ const rep_t bAbs = bInt & absMask;
+
+ if (aAbs > infRep || bAbs > infRep)
+ return GE_UNORDERED;
+ if ((aAbs | bAbs) == 0)
+ return GE_EQUAL;
+ if ((aInt & bInt) >= 0) {
+ if (aInt < bInt)
+ return GE_LESS;
+ else if (aInt == bInt)
+ return GE_EQUAL;
+ else
+ return GE_GREATER;
+ } else {
+ if (aInt > bInt)
+ return GE_LESS;
+ else if (aInt == bInt)
+ return GE_EQUAL;
+ else
+ return GE_GREATER;
+ }
+}
+
+static inline CMP_RESULT __unordXf2__(fp_t a, fp_t b) {
+ const rep_t aAbs = toRep(a) & absMask;
+ const rep_t bAbs = toRep(b) & absMask;
+ return aAbs > infRep || bAbs > infRep;
+}