resolve the comments

Co-authored-by: Copilot <copilot@github.com>

Author: 2 people

enzyme/Enzyme/GradientUtils.cpp

@@ -6323,6 +6323,34 @@ Value *GradientUtils::invertPointerM(Value *const oval, IRBuilder<> &BuilderM,
     switch (II->getIntrinsicID()) {
     default:
       goto end;
+#if LLVM_VERSION_MAJOR >= 12
+    case Intrinsic::smax:
+    case Intrinsic::smin:
+    case Intrinsic::umax:
+    case Intrinsic::umin: {
+      Value *val0 = invertPointerM(II->getArgOperand(0), bb, nullShadow);
+      Value *val1 = invertPointerM(II->getArgOperand(1), bb, nullShadow);
+      assert(val0->getType() == val1->getType());
+
+      auto rule = [&](Value *val0, Value *val1) {
+        Value *args[] = {val0, val1};
+        auto shadow = cast<CallInst>(
+            bb.CreateCall(II->getCalledFunction(), args,
+                          II->getName() + "'ipbi"));
+        shadow->setAttributes(II->getAttributes());
+        shadow->setCallingConv(II->getCallingConv());
+        shadow->setTailCallKind(II->getTailCallKind());
+        shadow->setDebugLoc(getNewFromOriginal(II->getDebugLoc()));
+        return shadow;
+      };
+
+      Value *shadow = applyChainRule(II->getType(), bb, rule, val0, val1);
+
+      invertedPointers.insert(
+          std::make_pair((const Value *)oval, InvertedPointerVH(this, shadow)));
+      return shadow;
+    }
+#endif
 #if LLVM_VERSION_MAJOR < 20
     case Intrinsic::nvvm_ldg_global_i:
     case Intrinsic::nvvm_ldg_global_p:
@@ -6573,13 +6601,6 @@ end:;
     return Constant::getNullValue(getShadowType(oval->getType()));
   }
 
-  if (looseTypeAnalysis && oval->getType()->isIntOrIntVectorTy()) {
-    auto *shadow = Constant::getNullValue(getShadowType(oval->getType()));
-    invertedPointers.insert(
-        std::make_pair((const Value *)oval, InvertedPointerVH(this, shadow)));
-    return shadow;
-  }
-
   if (CustomErrorHandler) {
     std::string str;
     raw_string_ostream ss(str);

enzyme/test/Enzyme/ReverseMode/loosetypes_umax.ll

@@ -13,7 +13,8 @@
 ; @llvm.umax.i32. Without the fix, this hits:
 ;   assert(0 && "cannot find deal with ptr that isnt arg")
 ;
-; The fix returns a zero shadow for integer values under loose-types analysis.
+; The fix handles llvm.umax as a binop-like intrinsic during shadow
+; reconstruction, instead of falling through to the generic no-shadow path.
 
 target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
@@ -73,9 +74,10 @@ declare void @__enzyme_autodiff(...)
 ; CHECK-SAME: i32 %face_idx, ptr noalias
 ; CHECK-SAME: %nbr)
 
-; Verify the primal block correctly computes and stores i32 umax with zero shadow
+; Verify the primal block computes both the original and shadow i32 umax values.
 ; CHECK:        %new_flag = tail call i32 @llvm.umax.i32(i32 %old_flag, i32 %flag)
-; CHECK-NEXT:   store i32 0, ptr %"flags_elem'ipg"
+; CHECK-NEXT:   %[[NEW_FLAG_IP:.+]] = {{(tail )?}}call i32 @llvm.umax.i32(i32 %{{.+}}, i32 %{{.+}})
+; CHECK-NEXT:   store i32 %[[NEW_FLAG_IP]], ptr %"flags_elem'ipg"
 ; CHECK-NEXT:   store i32 %new_flag, ptr %flags_elem
 
 ; Verify the reverse block correctly propagates float derivatives