From: Reid Spencer <rspencer@reidspencer.com>
Date: Sat, 24 Feb 2007 20:38:01 +0000 (+0000)
Subject: Fix the remainder shifting in KnuthDiv.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1050ec5cc42c4b1ff1702e09da9d520abe205b0d;p=oota-llvm.git

Fix the remainder shifting in KnuthDiv.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34562 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Support/APInt.cpp b/lib/Support/APInt.cpp
index 7f2aa429247..60c940c566d 100644
--- a/lib/Support/APInt.cpp
+++ b/lib/Support/APInt.cpp
@@ -1134,12 +1134,19 @@ static void KnuthDiv(uint32_t *u, uint32_t *v, uint32_t *q, uint32_t* r,
     // The value d is expressed by the "shift" value above since we avoided
     // multiplication by d by using a shift left. So, all we have to do is
     // shift right here. In order to mak
-    uint32_t carry = 0;
-    DEBUG(cerr << "KnuthDiv: remainder:");
-    for (int i = n-1; i >= 0; i--) {
-      r[i] = (u[i] >> shift) | carry;
-      carry = u[i] << shift;
-      DEBUG(cerr << " " << r[i]);
+    if (shift) {
+      uint32_t carry = 0;
+      DEBUG(cerr << "KnuthDiv: remainder:");
+      for (int i = n-1; i >= 0; i--) {
+        r[i] = (u[i] >> shift) | carry;
+        carry = u[i] << (32 - shift);
+        DEBUG(cerr << " " << r[i]);
+      }
+    } else {
+      for (int i = n-1; i >= 0; i--) {
+        r[i] = u[i];
+        DEBUG(cerr << " " << r[i]);
+      }
     }
     DEBUG(cerr << '\n');
   }