Void augmented (rust-lang#351)

Author: wsmoses

enzyme/Enzyme/Enzyme.cpp

@@ -980,10 +980,6 @@ class Enzyme : public ModulePass {
         tape = Builder.CreateLoad(
             Builder.CreatePointerCast(AL, PointerType::getUnqual(tapeType)));
       }
-      llvm::errs() << *CI->getParent() << "\n";
-      llvm::errs() << *CI->getParent() << "\n";
-      llvm::errs() << *tape << "\n";
-      llvm::errs() << *tapeType << "\n";
       assert(tape->getType() == tapeType);
       args.push_back(tape);
     }
@@ -1056,7 +1052,8 @@ class Enzyme : public ModulePass {
       }
     }
 
-    if (!diffret->getType()->isEmptyTy() && !diffret->getType()->isVoidTy()) {
+    if (!diffret->getType()->isEmptyTy() && !diffret->getType()->isVoidTy() &&
+        !CI->getType()->isEmptyTy() && !CI->getType()->isVoidTy()) {
       if (diffret->getType() == CI->getType()) {
         CI->replaceAllUsesWith(diffret);
       } else if (mode == DerivativeMode::ReverseModePrimal) {

enzyme/test/Enzyme/ReverseMode/splitSize4.ll

@@ -0,0 +1,38 @@
+; RUN: %opt < %s %loadEnzyme -enzyme -enzyme-preopt=false -mem2reg -instsimplify -simplifycfg -S | FileCheck %s
+
+; Function Attrs: noinline nounwind readnone uwtable
+define double @tester(double* %x) {
+entry:
+  %gep = getelementptr double, double* %x, i32 1
+  %y = load double, double* %x
+  %z = load double, double* %gep
+  %res = fmul fast double %y, %z
+  ret double %res
+}
+
+define void @test_derivative(double* %x, double* %dx) {
+entry:
+  %size = call i64 (double (double*)*, ...) @__enzyme_augmentsize(double (double*)* nonnull @tester, metadata !"enzyme_dup")
+  %cache = alloca i8, i64 %size, align 1
+  call void (double (double*)*, ...) @__enzyme_augmentfwd(double (double*)* nonnull @tester, metadata !"enzyme_allocated", i64 %size, metadata !"enzyme_tape", i8* %cache, double* %x, double* %dx)
+  tail call void (double (double*)*, ...) @__enzyme_reverse(double (double*)* nonnull @tester, metadata !"enzyme_allocated", i64 %size, metadata !"enzyme_tape", i8* %cache, double* %x, double* %dx)
+  ret void
+}
+
+; Function Attrs: nounwind
+declare void @__enzyme_augmentfwd(double (double*)*, ...)
+declare i64 @__enzyme_augmentsize(double (double*)*, ...)
+declare void @__enzyme_reverse(double (double*)*, ...)
+
+; CHECK: define void @test_derivative(double* %x, double* %dx)
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   %cache = alloca i8, i64 16
+; CHECK-NEXT:   %0 = call { { double, double }, double } @augmented_tester(double* %x, double* %dx)
+; CHECK-NEXT:   %1 = extractvalue { { double, double }, double } %0, 0
+; CHECK-NEXT:   %2 = bitcast i8* %cache to { double, double }*
+; CHECK-NEXT:   store { double, double } %1, { double, double }* %2
+; CHECK-NEXT:   %3 = bitcast i8* %cache to { double, double }*
+; CHECK-NEXT:   %4 = load { double, double }, { double, double }* %3
+; CHECK-NEXT:   call void @diffetester(double* %x, double* %dx, double 1.000000e+00, { double, double } %4)
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }