[llvm] [ADT][APInt] add sfloordiv_ov APInt's member function (PR #84720)

[Jay Foad via llvm-commits]

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@@ -3048,6 +3049,91 @@ TEST(APIntTest, smul_ov) {
       }
 }
 
+TEST(APIntTest, sfloordiv_ov) {
+  // test negative quotient
+  {
+    APInt divisor(32, -3, true);
+    APInt dividend(32, 2, true);
+    bool Overflow = false;
+    auto quotient = divisor.sfloordiv_ov(dividend, Overflow);
+    EXPECT_FALSE(Overflow);
+    EXPECT_EQ(-2, quotient.getSExtValue());
+  }
+  // test positive quotient
+  {
+    APInt divisor(32, 3, true);
+    APInt dividend(32, 2, true);
+    bool Overflow = false;
+    auto quotient = divisor.sfloordiv_ov(dividend, Overflow);
+    EXPECT_FALSE(Overflow);
+    EXPECT_EQ(1, quotient.getSExtValue());
+  }
+  // int8 test overflow
+  {
+    using IntTy = int8_t;
+    APInt divisor(8 * sizeof(IntTy), std::numeric_limits<IntTy>::lowest(),
+                  true);
+    APInt dividend(8 * sizeof(IntTy), IntTy(-1), true);
+    bool Overflow = false;
+    (void)divisor.sfloordiv_ov(dividend, Overflow);
+    EXPECT_TRUE(Overflow);
+  }
+  // int16 test overflow
+  {
+    using IntTy = int16_t;
+    APInt divisor(8 * sizeof(IntTy), std::numeric_limits<IntTy>::lowest(),
+                  true);
+    APInt dividend(8 * sizeof(IntTy), IntTy(-1), true);
+    bool Overflow = false;
+    (void)divisor.sfloordiv_ov(dividend, Overflow);
+    EXPECT_TRUE(Overflow);
+  }
+  // int32 test overflow
+  {
+    using IntTy = int32_t;
+    APInt divisor(8 * sizeof(IntTy), std::numeric_limits<IntTy>::lowest(),
+                  true);
+    APInt dividend(8 * sizeof(IntTy), IntTy(-1), true);
+    bool Overflow = false;
+    (void)divisor.sfloordiv_ov(dividend, Overflow);
+    EXPECT_TRUE(Overflow);
+  }
+  // int64 test overflow
+  {
+    using IntTy = int64_t;
+    APInt divisor(8 * sizeof(IntTy), std::numeric_limits<IntTy>::lowest(),
+                  true);
+    APInt dividend(8 * sizeof(IntTy), IntTy(-1), true);
+    bool Overflow = false;
+    (void)divisor.sfloordiv_ov(dividend, Overflow);
+    EXPECT_TRUE(Overflow);
+  }
+  // test all of int8
+  {
+    bool Overflow = true;
+    for (int i = -128; i < 128; ++i) {
+      for (int j = -128; j < 128; ++j) {
+        if (j == 0 || (i == -128 && j == -1))
+          continue;
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jayfoad wrote:

`EXPECT_TRUE(Overflow)` here? Then maybe you don't need so many ad hoc tests above?

https://github.com/llvm/llvm-project/pull/84720