[llvm] 7b771ed - [APInt] Fix tests that had wrong assumption about sdivs with negative quotient.

[Tim Shen via llvm-commits]

Author: Tim Shen
Date: 2020-01-21T13:53:01-08:00
New Revision: 7b771ed448487705237868f705da17b40c6bfe82

URL: https://github.com/llvm/llvm-project/commit/7b771ed448487705237868f705da17b40c6bfe82
DIFF: https://github.com/llvm/llvm-project/commit/7b771ed448487705237868f705da17b40c6bfe82.diff

LOG: [APInt] Fix tests that had wrong assumption about sdivs with negative quotient.

Reviewers: sanjoy

Subscribers: bixia, dexonsmith, sanjoy.google, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70156

Added: 
    

Modified: 
    llvm/unittests/ADT/APIntTest.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index b6fee5b7ff1a..6e87c70d5632 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -2604,31 +2604,36 @@ TEST(APIntTest, RoundingSDiv) {
       EXPECT_EQ(0, APIntOps::RoundingSDiv(Zero, A, APInt::Rounding::TOWARD_ZERO));
     }
 
-    for (uint64_t Bi = -128; Bi <= 127; Bi++) {
+    for (int64_t Bi = -128; Bi <= 127; Bi++) {
       if (Bi == 0)
         continue;
 
       APInt B(8, Bi);
+      APInt QuoTowardZero = A.sdiv(B);
       {
         APInt Quo = APIntOps::RoundingSDiv(A, B, APInt::Rounding::UP);
-        auto Prod = Quo.sext(16) * B.sext(16);
-        EXPECT_TRUE(Prod.uge(A));
-        if (Prod.ugt(A)) {
-          EXPECT_TRUE(((Quo - 1).sext(16) * B.sext(16)).ult(A));
+        if (A.srem(B).isNullValue()) {
+          EXPECT_EQ(QuoTowardZero, Quo);
+        } else if (A.isNegative() !=
+                   B.isNegative()) { // if the math quotient is negative.
+          EXPECT_EQ(QuoTowardZero, Quo);
+        } else {
+          EXPECT_EQ(QuoTowardZero + 1, Quo);
         }
       }
       {
         APInt Quo = APIntOps::RoundingSDiv(A, B, APInt::Rounding::DOWN);
-        auto Prod = Quo.sext(16) * B.sext(16);
-        EXPECT_TRUE(Prod.ule(A));
-        if (Prod.ult(A)) {
-          EXPECT_TRUE(((Quo + 1).sext(16) * B.sext(16)).ugt(A));
+        if (A.srem(B).isNullValue()) {
+          EXPECT_EQ(QuoTowardZero, Quo);
+        } else if (A.isNegative() !=
+                   B.isNegative()) { // if the math quotient is negative.
+          EXPECT_EQ(QuoTowardZero - 1, Quo);
+        } else {
+          EXPECT_EQ(QuoTowardZero, Quo);
         }
       }
-      {
-        APInt Quo = A.sdiv(B);
-        EXPECT_EQ(Quo, APIntOps::RoundingSDiv(A, B, APInt::Rounding::TOWARD_ZERO));
-      }
+      EXPECT_EQ(QuoTowardZero,
+                APIntOps::RoundingSDiv(A, B, APInt::Rounding::TOWARD_ZERO));
     }
   }
 }