From 0c276e5dcbf101c0f595391c1a55a4eeecc5f6d7 Mon Sep 17 00:00:00 2001
From: Matthew Hall <matthew.hall3@outlook.com>
Date: Wed, 25 Sep 2024 10:06:21 -0400
Subject: [PATCH] Fixed handling of +/-0 in optimizer simplifiers for
 fmin/fmax/dmin/dmax nodes

when folding the min/max nodes to constants, max(+0, -0) now correctly folds to +0, and min(+0, -0) now correctly folds to -0

Signed-off-by: Matthew Hall <matthew.hall3@outlook.com>
---
 compiler/optimizer/OMRSimplifierHandlers.cpp | 40 +++++++++++++++++---
 1 file changed, 34 insertions(+), 6 deletions(-)

diff --git a/compiler/optimizer/OMRSimplifierHandlers.cpp b/compiler/optimizer/OMRSimplifierHandlers.cpp
index b53b85afa01..4518f171ffa 100644
--- a/compiler/optimizer/OMRSimplifierHandlers.cpp
+++ b/compiler/optimizer/OMRSimplifierHandlers.cpp
@@ -17762,10 +17762,24 @@ TR::Node *fmaxminSimplifier(TR::Node * node, TR::Block * block, TR::Simplifier *
          fmin = fmax = secondChild->getFloat();
       else
          {
-         if (firstChild->getFloat() <= secondChild->getFloat())
+         float first = firstChild->getFloat();
+         float second = secondChild->getFloat();
+         int nZeroBits = 0x80000000;
+         if (first <= second)
             {
-            fmin = firstChild->getFloat();
-            fmax = secondChild->getFloat();
+            if (first == second && first == 0)
+               {
+               int firstBits = *(int *)(&first);
+               int secondBits = *(int *)(&second);
+               int sign = firstBits & nZeroBits;
+               fmin = sign < 0 ? first : second;
+               fmax = sign < 0 ? second : first;
+               }
+            else
+               {
+               fmin = firstChild->getFloat();
+               fmax = secondChild->getFloat();
+               }
             }
          else
             {
@@ -17797,10 +17811,24 @@ TR::Node *dmaxminSimplifier(TR::Node * node, TR::Block * block, TR::Simplifier *
          min = max = secondChild->getDouble();
       else
          {
-         if (firstChild->getDouble() <= secondChild->getDouble())
+         double first = firstChild->getDouble();
+         double second = secondChild->getDouble();
+         long nZeroBits = 0x8000000000000000L;
+         if (first <= second)
             {
-            min = firstChild->getDouble();
-            max = secondChild->getDouble();
+            if (first == second && first == 0)
+               {
+               long firstBits = *(long *)(&first);
+               long secondBits = *(long *)(&second);
+               long sign = firstBits & nZeroBits;
+               min = sign < 0 ? first : second;
+               max = sign < 0 ? second : first;
+               }
+            else
+               {
+                  min = firstChild->getDouble();
+                  max = secondChild->getDouble();
+               }
             }
          else
             {