From d0c413bc8a4195b7175f03db662494603b7ef3f2 Mon Sep 17 00:00:00 2001
From: PHILO-HE <feilong.he@intel.com>
Date: Wed, 13 Mar 2024 15:44:09 +0800
Subject: [PATCH] Use int32_max that will be replaced by partition end index at
 last

---
 velox/exec/Window.cpp | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/velox/exec/Window.cpp b/velox/exec/Window.cpp
index 3ef2181c99d3..b963fc059cbe 100644
--- a/velox/exec/Window.cpp
+++ b/velox/exec/Window.cpp
@@ -287,7 +287,8 @@ void updateKRowsOffsetsColumn(
     auto startValue = (int64_t)(startRow + i) + precedingFactor * offsets[i];
     // Considers integer overflow case.
     if (startValue != (int32_t)startValue) {
-      rawFrameBounds[i] = startValue < 0 ? 0 : numRows - 1;
+      // computeValidFrames will handle INT32_MAX to compute a valid index.
+      rawFrameBounds[i] = startValue < 0 ? 0 : INT32_MAX;
     } else {
       rawFrameBounds[i] = startValue;
     }
@@ -295,11 +296,11 @@ void updateKRowsOffsetsColumn(
 }
 
 // Get the start index that integer overflow can happen for kFollowing.
-FOLLY_ALWAYS_INLINE int32_t getOverflowStart(int64_t constantOffset) {
-  if (constantOffset > (int64_t)std::numeric_limits<int32_t>::max()) {
+FOLLY_ALWAYS_INLINE int32_t getOverflowStart(int64_t startValue) {
+  if (startValue > (int64_t)INT32_MAX) {
     return 0;
   } else {
-    return std::numeric_limits<int32_t>::max() - constantOffset + 1;
+    return INT32_MAX - startValue + 1;
   }
 }
 
@@ -318,8 +319,8 @@ void Window::updateKRowsFrameBounds(
 
     if (isKPreceding) {
       // Considers a very large int64 constantOffset is used.
-      if (startValue < std::numeric_limits<int32_t>::min()) {
-        std::fill_n(rawFrameBounds, numRows, startRow);
+      if (startValue < INT32_MIN) {
+        std::fill_n(rawFrameBounds, numRows, 0);
         return;
       }
       // Integer overflow cannot happen.
@@ -327,14 +328,13 @@ void Window::updateKRowsFrameBounds(
       return;
     }
     // KFollowing.
-    auto overflowStart = getOverflowStart(constantOffset);
+    auto overflowStart = getOverflowStart(startValue);
     if (overflowStart >= 0 && overflowStart < numRows) {
       std::iota(rawFrameBounds, rawFrameBounds + overflowStart, startValue);
-      // For remaining, set with the largest index for this partition.
+      // For remaining, use INT32_MAX, which will be converted to valid index
+      // by computeValidFrames.
       std::fill_n(
-          rawFrameBounds + overflowStart,
-          numRows - overflowStart,
-          startRow + numRows - 1);
+          rawFrameBounds + overflowStart, numRows - overflowStart, INT32_MAX);
       return;
     }
     // Integer overflow cannot happen.