1 files changed, 98 insertions, 0 deletions
diff --git a/contrib/llvm-project/compiler-rt/lib/builtins/ppc/fixtfdi.c b/contrib/llvm-project/compiler-rt/lib/builtins/ppc/fixtfdi.c
new file mode 100644
index 000000000000..a97aaf095846
--- /dev/null
+++ b/contrib/llvm-project/compiler-rt/lib/builtins/ppc/fixtfdi.c
@@ -0,0 +1,98 @@
+// 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
+
+// int64_t __fixunstfdi(long double x);
+// This file implements the PowerPC 128-bit double-double -> int64_t conversion
+
+#include "../int_math.h"
+#include "DD.h"
+
+uint64_t __fixtfdi(long double input) {
+  const DD x = {.ld = input};
+  const doublebits hibits = {.d = x.s.hi};
+
+  const uint32_t absHighWord =
+      (uint32_t)(hibits.x >> 32) & UINT32_C(0x7fffffff);
+  const uint32_t absHighWordMinusOne = absHighWord - UINT32_C(0x3ff00000);
+
+  // If (1.0 - tiny) <= input < 0x1.0p63:
+  if (UINT32_C(0x03f00000) > absHighWordMinusOne) {
+    // Do an unsigned conversion of the absolute value, then restore the sign.
+    const int unbiasedHeadExponent = absHighWordMinusOne >> 20;
+
+    int64_t result = hibits.x & INT64_C(0x000fffffffffffff); // mantissa(hi)
+    result |= INT64_C(0x0010000000000000); // matissa(hi) with implicit bit
+    result <<= 10; // mantissa(hi) with one zero preceding bit.
+
+    const int64_t hiNegationMask = ((int64_t)(hibits.x)) >> 63;
+
+    // If the tail is non-zero, we need to patch in the tail bits.
+    if (0.0 != x.s.lo) {
+      const doublebits lobits = {.d = x.s.lo};
+      int64_t tailMantissa = lobits.x & INT64_C(0x000fffffffffffff);
+      tailMantissa |= INT64_C(0x0010000000000000);
+
+      // At this point we have the mantissa of |tail|
+      // We need to negate it if head and tail have different signs.
+      const int64_t loNegationMask = ((int64_t)(lobits.x)) >> 63;
+      const int64_t negationMask = loNegationMask ^ hiNegationMask;
+      tailMantissa = (tailMantissa ^ negationMask) - negationMask;
+
+      // Now we have the mantissa of tail as a signed 2s-complement integer
+
+      const int biasedTailExponent = (int)(lobits.x >> 52) & 0x7ff;
+
+      // Shift the tail mantissa into the right position, accounting for the
+      // bias of 10 that we shifted the head mantissa by.
+      tailMantissa >>=
+          (unbiasedHeadExponent - (biasedTailExponent - (1023 - 10)));
+
+      result += tailMantissa;
+    }
+
+    result >>= (62 - unbiasedHeadExponent);
+
+    // Restore the sign of the result and return
+    result = (result ^ hiNegationMask) - hiNegationMask;
+    return result;
+  }
+
+  // Edge cases handled here:
+
+  // |x| < 1, result is zero.
+  if (1.0 > crt_fabs(x.s.hi))
+    return INT64_C(0);
+
+  // x very close to INT64_MIN, care must be taken to see which side we are on.
+  if (x.s.hi == -0x1.0p63) {
+
+    int64_t result = INT64_MIN;
+
+    if (0.0 < x.s.lo) {
+      // If the tail is positive, the correct result is something other than
+      // INT64_MIN. we'll need to figure out what it is.
+
+      const doublebits lobits = {.d = x.s.lo};
+      int64_t tailMantissa = lobits.x & INT64_C(0x000fffffffffffff);
+      tailMantissa |= INT64_C(0x0010000000000000);
+
+      // Now we negate the tailMantissa
+      tailMantissa = (tailMantissa ^ INT64_C(-1)) + INT64_C(1);
+
+      // And shift it by the appropriate amount
+      const int biasedTailExponent = (int)(lobits.x >> 52) & 0x7ff;
+      tailMantissa >>= 1075 - biasedTailExponent;
+
+      result -= tailMantissa;
+    }
+
+    return result;
+  }
+
+  // Signed overflows, infinities, and NaNs
+  if (x.s.hi > 0.0)
+    return INT64_MAX;
+  else
+    return INT64_MIN;
+}