From 82d61af3a490154ad1c0ae2fe00c561095854897 Mon Sep 17 00:00:00 2001
From: Antonio Sanchez <cantonios@google.com>
Date: Wed, 3 Mar 2021 19:22:15 -0800
Subject: Fix rint SSE/NEON again, using optimization barrier.

This is a new version of !423, which failed for MSVC.

Defined `EIGEN_OPTIMIZATION_BARRIER(X)` that uses inline assembly to
prevent operations involving `X` from crossing that barrier. Should
work on most `GNUC` compatible compilers (MSVC doesn't seem to need
this). This is a modified version adapted from what was used in
`psincos_float` and tested on more platforms
(see #1674, https://godbolt.org/z/73ezTG).

Modified `rint` to use the barrier to prevent the add/subtract rounding
trick from being optimized away.

Also fixed an edge case for large inputs that get bumped up a power of two
and ends up rounding away more than just the fractional part.  If we are
over `2^digits` then just return the input.  This edge case was missed in
the test since the test was comparing approximate equality, which was still
satisfied.  Adding a strict equality option catches it.
---
 test/packetmath_test_shared.h | 37 ++++++++++++++++++++++++++++++-------
 1 file changed, 30 insertions(+), 7 deletions(-)

(limited to 'test/packetmath_test_shared.h')

diff --git a/test/packetmath_test_shared.h b/test/packetmath_test_shared.h
index 027715a89..8624fe2fe 100644
--- a/test/packetmath_test_shared.h
+++ b/test/packetmath_test_shared.h
@@ -78,13 +78,18 @@ bool isApproxAbs(const Scalar& a, const Scalar& b, const typename NumTraits<Scal
   return internal::isMuchSmallerThan(a-b, refvalue);
 }
 
+template<typename Scalar>
+inline void print_mismatch(const Scalar* ref, const Scalar* vec, int size) {
+  std::cout << "ref: [" << Map<const Matrix<Scalar,1,Dynamic> >(ref,size) << "]" << " != vec: [" << Map<const Matrix<Scalar,1,Dynamic> >(vec,size) << "]\n";
+}
+
 template<typename Scalar> bool areApproxAbs(const Scalar* a, const Scalar* b, int size, const typename NumTraits<Scalar>::Real& refvalue)
 {
   for (int i=0; i<size; ++i)
   {
     if (!isApproxAbs(a[i],b[i],refvalue))
     {
-      std::cout << "ref: [" << Map<const Matrix<Scalar,1,Dynamic> >(a,size) << "]" << " != vec: [" << Map<const Matrix<Scalar,1,Dynamic> >(b,size) << "]\n";
+      print_mismatch(a, b, size);
       return false;
     }
   }
@@ -95,13 +100,23 @@ template<typename Scalar> bool areApprox(const Scalar* a, const Scalar* b, int s
 {
   for (int i=0; i<size; ++i)
   {
-    if (a[i]!=b[i] && !internal::isApprox(a[i],b[i]))
+    if ( a[i]!=b[i] && !internal::isApprox(a[i],b[i]) 
+         && !((numext::isnan)(a[i]) && (numext::isnan)(b[i])) )
+    {
+      print_mismatch(a, b, size);
+      return false;
+    }
+  }
+  return true;
+}
+
+template<typename Scalar> bool areEqual(const Scalar* a, const Scalar* b, int size)
+{
+  for (int i=0; i<size; ++i)
+  {
+    if ( (a[i] != b[i]) && !((numext::isnan)(a[i]) && (numext::isnan)(b[i])) )
     {
-      if((numext::isnan)(a[i]) && (numext::isnan)(b[i]))
-      {
-        continue;
-      }
-      std::cout << "ref: [" << Map<const Matrix<Scalar,1,Dynamic> >(a,size) << "]" << " != vec: [" << Map<const Matrix<Scalar,1,Dynamic> >(b,size) << "]\n";
+      print_mismatch(a, b, size);
       return false;
     }
   }
@@ -178,6 +193,14 @@ struct packet_helper<false,Packet>
   VERIFY(test::areApprox(ref, data2, PacketSize) && #POP); \
 }
 
+#define CHECK_CWISE1_EXACT_IF(COND, REFOP, POP) if(COND) { \
+  test::packet_helper<COND,Packet> h; \
+  for (int i=0; i<PacketSize; ++i) \
+    ref[i] = Scalar(REFOP(data1[i])); \
+  h.store(data2, POP(h.load(data1))); \
+  VERIFY(test::areEqual(ref, data2, PacketSize) && #POP); \
+}
+
 #define CHECK_CWISE2_IF(COND, REFOP, POP) if(COND) { \
   test::packet_helper<COND,Packet> h; \
   for (int i=0; i<PacketSize; ++i) \
-- 
cgit v1.2.3