1 files changed, 13 insertions, 11 deletions
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 1054c7935b5..fd7a4de6903 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -1958,20 +1958,22 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
         Lower = (-Upper) + 1;
       }
     } else if (match(LHS, m_SDiv(m_Value(), m_ConstantInt(CI2)))) {
-      // 'sdiv x, CI2' produces [INT_MIN / CI2, INT_MAX / CI2].
       APInt IntMin = APInt::getSignedMinValue(Width);
       APInt IntMax = APInt::getSignedMaxValue(Width);
-      APInt Val = CI2->getValue().abs();
-      if (!Val.isMinValue()) {
+      APInt Val = CI2->getValue();
+      if (Val.isAllOnesValue()) {
+        // 'sdiv x, -1' produces [INT_MIN + 1, INT_MAX]
+        //    where CI2 != -1 and CI2 != 0 and CI2 != 1
+        Lower = IntMin + 1;
+        Upper = IntMax + 1;
+      } else if (Val.countLeadingZeros() < Width - 1) {
+        // 'sdiv x, CI2' produces [INT_MIN / CI2, INT_MAX / CI2]
+        //    where CI2 != -1 and CI2 != 0 and CI2 != 1
         Lower = IntMin.sdiv(Val);
-        APInt Rem;
-        APInt::sdivrem(IntMax, Val, Upper, Rem);
-        // We may need to round the result of the INT_MAX / CI2 calculation up
-        // if we see that the division was not exact.
-        if (Rem.isMinValue())
-          Upper = Upper + 1;
-        else
-          Upper = Upper + 2;
+        Upper = IntMax.sdiv(Val);
+        if (Lower.sgt(Upper))
+          std::swap(Lower, Upper);
+        Upper = Upper + 1;
         assert(Upper != Lower && "Upper part of range has wrapped!");
       }
     } else if (match(LHS, m_LShr(m_Value(), m_ConstantInt(CI2)))) {