Index: llvm/lib/Analysis/InstructionSimplify.cpp
===================================================================
--- llvm/lib/Analysis/InstructionSimplify.cpp
+++ llvm/lib/Analysis/InstructionSimplify.cpp
@@ -1109,6 +1109,10 @@
   if (match(Op1, m_SExt(m_Value(X))) && X->getType()->isIntOrIntVectorTy(1))
     return ConstantInt::getNullValue(Op0->getType());
 
+  // If the two operands are negatived, return 0.
+  if (isKnownNegation(Op0, Op1))
+    return ConstantInt::getNullValue(Op0->getType());
+
   return simplifyRem(Instruction::SRem, Op0, Op1, Q, MaxRecurse);
 }
 
Index: llvm/test/Transforms/InstSimplify/srem.ll
===================================================================
--- llvm/test/Transforms/InstSimplify/srem.ll
+++ llvm/test/Transforms/InstSimplify/srem.ll
@@ -1,10 +1,9 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -instsimplify -S | FileCheck %s
 
 define i32 @negated_operand(i32 %x) {
 ; CHECK-LABEL: @negated_operand(
-; CHECK-NEXT:    [[NEGX:%.*]] = sub i32 0, [[X:%.*]]
-; CHECK-NEXT:    [[REM:%.*]] = srem i32 [[NEGX]], [[X]]
-; CHECK-NEXT:    ret i32 [[REM]]
+; CHECK-NEXT:    ret i32 0
 ;
   %negx = sub i32 0, %x
   %rem = srem i32 %negx, %x
@@ -13,37 +12,49 @@
 
 define <2 x i32> @negated_operand_commute_vec(<2 x i32> %x) {
 ; CHECK-LABEL: @negated_operand_commute_vec(
-; CHECK-NEXT:    [[NEGX:%.*]] = sub nsw <2 x i32> zeroinitializer, [[X:%.*]]
-; CHECK-NEXT:    [[REM:%.*]] = srem <2 x i32> [[NEGX]], [[X]]
-; CHECK-NEXT:    ret <2 x i32> [[REM]]
+; CHECK-NEXT:    ret <2 x i32> zeroinitializer
 ;
-  %negx = sub nsw <2 x i32> zeroinitializer, %x
+  %negx = sub <2 x i32> zeroinitializer, %x
   %rem = srem <2 x i32> %negx, %x
   ret <2 x i32> %rem
 }
 
 define i32 @knownnegation(i32 %x, i32 %y) {
 ; CHECK-LABEL: @knownnegation(
-; CHECK-NEXT:    [[XY:%.*]] = sub nsw i32 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[YX:%.*]] = sub nsw i32 [[Y]], [[X]]
-; CHECK-NEXT:    [[REM:%.*]] = srem i32 [[XY]], [[YX]]
-; CHECK-NEXT:    ret i32 [[REM]]
+; CHECK-NEXT:    ret i32 0
 ;
-  %xy = sub nsw i32 %x, %y
-  %yx = sub nsw i32 %y, %x
+  %xy = sub i32 %x, %y
+  %yx = sub i32 %y, %x
   %rem = srem i32 %xy, %yx
   ret i32 %rem
 }
 
 define <2 x i32> @knownnegation_commute_vec(<2 x i32> %x, <2 x i32> %y) {
 ; CHECK-LABEL: @knownnegation_commute_vec(
-; CHECK-NEXT:    [[XY:%.*]] = sub nsw <2 x i32> [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[YX:%.*]] = sub nsw <2 x i32> [[Y]], [[X]]
-; CHECK-NEXT:    [[REM:%.*]] = srem <2 x i32> [[XY]], [[YX]]
-; CHECK-NEXT:    ret <2 x i32> [[REM]]
+; CHECK-NEXT:    ret <2 x i32> zeroinitializer
 ;
-  %xy = sub nsw <2 x i32> %x, %y
-  %yx = sub nsw <2 x i32> %y, %x
+  %xy = sub <2 x i32> %x, %y
+  %yx = sub <2 x i32> %y, %x
   %rem = srem <2 x i32> %xy, %yx
   ret <2 x i32> %rem
 }
+
+define <3 x i32> @negated_operand_vec_undef(<3 x i32> %x) {
+; CHECK-LABEL: @negated_operand_vec_undef(
+; CHECK-NEXT:    ret <3 x i32> zeroinitializer
+;
+  %negx = sub <3 x i32> <i32 0, i32 undef, i32 0>, %x
+  %rem = srem <3 x i32> %negx, %x
+  ret <3 x i32> %rem
+}
+
+define <2 x i32> @negated_operand_vec_nonsplat(<2 x i32> %x) {
+; CHECK-LABEL: @negated_operand_vec_nonsplat(
+; CHECK-NEXT:    [[NEGX:%.*]] = sub <2 x i32> <i32 0, i32 1>, [[X:%.*]]
+; CHECK-NEXT:    [[REM:%.*]] = srem <2 x i32> [[NEGX]], [[X]]
+; CHECK-NEXT:    ret <2 x i32> [[REM]]
+;
+  %negx = sub <2 x i32> <i32 0, i32 1>, %x ; not 0, don't fold
+  %rem = srem <2 x i32> %negx, %x
+  ret <2 x i32> %rem
+}