fix subtle if bug

EnzymeAD · wsmoses · Oct 15, 2019 · Oct 10, 2019 · Oct 10, 2019 · Oct 12, 2019
commit d04d3e437c9e0a5bfc995e7a8a1d6f462f6cd977
diff --git a/enzyme/Enzyme/ActiveVariable.cpp b/enzyme/Enzyme/ActiveVariable.cpp
@@ -473,15 +473,19 @@ bool isconstantM(Instruction* inst, SmallPtrSetImpl<Value*> &constants, SmallPtr
                     return false;
                 }
             }
-
-            constants.insert(inst);
-            constants.insert(constants2.begin(), constants2.end());
-            constants.insert(constants_tmp.begin(), constants_tmp.end());
-            //if (directions == 3)
-            //  nonconstant.insert(nonconstant2.begin(), nonconstant2.end());
-            if (printconst)
-              llvm::errs() << "constant(" << (int)directions << ")  call:" << *inst << "\n";
-            return true;
+
+            //! TODO: Really need an attribute that determines whether a function can access a global (not even necessarily read)
+            //if (ci->hasFnAttr(Attribute::ReadNone) || ci->hasFnAttr(Attribute::ArgMemOnly)) 
+            {
+                constants.insert(inst);
+                constants.insert(constants2.begin(), constants2.end());
+                constants.insert(constants_tmp.begin(), constants_tmp.end());
+                //if (directions == 3)
+                //  nonconstant.insert(nonconstant2.begin(), nonconstant2.end());
+                if (printconst)
+                  llvm::errs() << "constant(" << (int)directions << ")  call:" << *inst << "\n";
+                return true;
+            }
         } else {
             for(auto& a: inst->operands()) {
                 if (!isconstantValueM(a, constants2, nonconstant2, retvals, originalInstructions, UP)) {

diff --git a/enzyme/Enzyme/GradientUtils.cpp b/enzyme/Enzyme/GradientUtils.cpp
@@ -958,6 +958,12 @@ void GradientUtils::branchToCorrespondingTarget(BasicBlock* ctx, IRBuilder <>& B
                   llvm::errs() << *branch << "\n";
                   llvm_unreachable("unknown successor for replacephi");
               }
+              if (&*BuilderM.GetInsertPoint() == pair.second) {
+                if (pair.second->getNextNode())
+                  BuilderM.SetInsertPoint(pair.second->getNextNode());
+                else
+                  BuilderM.SetInsertPoint(pair.second->getParent());
+              }
               pair.second->replaceAllUsesWith(val);
               pair.second->eraseFromParent();
           }

diff --git a/enzyme/test/Enzyme/insertsort.ll b/enzyme/test/Enzyme/insertsort.ll
@@ -1,5 +1,6 @@
 ; RUN: opt < %s %loadEnzyme -enzyme -enzyme_preopt=false -inline -mem2reg -instcombine -correlated-propagation -adce -instcombine -simplifycfg -early-cse -simplifycfg -S | FileCheck %s
 ; XFAIL: *
+
 ; Function Attrs: noinline norecurse nounwind uwtable
 define dso_local void @insertion_sort_inner(float* nocapture %array, i32 %i) local_unnamed_addr #0 {
 entry:

diff --git a/enzyme/test/Enzyme/recursum.ll b/enzyme/test/Enzyme/recursum.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s %loadEnzyme -enzyme -enzyme_preopt=false -inline -mem2reg -instsimplify -adce -loop-deletion -correlated-propagation -simplifycfg -ipconstprop -deadargelim -S -early-cse -instcombine -print-after-all | FileCheck %s
+; RUN: opt < %s %loadEnzyme -enzyme -enzyme_preopt=false -inline -mem2reg -instsimplify -adce -loop-deletion -correlated-propagation -simplifycfg -ipconstprop -deadargelim -S -early-cse -instcombine -jump-threading | FileCheck %s
 
 ; #include <stdio.h>
 ; #include <stdlib.h>
@@ -67,37 +67,29 @@ attributes #2 = { nounwind }
 ; CHECK: define internal {{(dso_local )?}}double @differecsum.1(double* %x, double* %"x'", i32 %n)
 ; CHECK-NEXT: entry:
 ; CHECK-NEXT:   switch i32 %n, label %if.end3 [
-; CHECK-NEXT:     i32 0, label %invertreturn
-; CHECK-NEXT:     i32 1, label %if.then2
+; CHECK-NEXT:     i32 0, label %invertentry
+; CHECK-NEXT:     i32 1, label %invertif.then2
 ; CHECK-NEXT:   ]
 
-; CHECK: if.then2:                                         ; preds = %entry
-; CHECK-NEXT:   %0 = load double, double* %x, align 8, !tbaa !2
-; CHECK-NEXT:   br label %invertreturn
-
 ; CHECK: if.end3:                                          ; preds = %entry
 ; CHECK-NEXT:   %div = lshr i32 %n, 1
 ; CHECK-NEXT:   %idx.ext = zext i32 %div to i64
 ; CHECK-NEXT:   %add.ptr = getelementptr inbounds double, double* %x, i64 %idx.ext
 ; CHECK-NEXT:   %"add.ptr'ipg" = getelementptr double, double* %"x'", i64 %idx.ext
-; CHECK-NEXT:   %1 = sub i32 %n, %div
-; CHECK-NEXT:   %2 = call double @differecsum.1(double* %add.ptr, double* %"add.ptr'ipg", i32 %1)
-; CHECK-NEXT:   %3 = call double @differecsum.1(double* %x, double* %"x'", i32 %div)
-; CHECK-NEXT:   %add = fadd fast double %2, %3
+; CHECK-NEXT:   %[[sub:.+]] = sub i32 %n, %div
+; CHECK-NEXT:   %[[dsum1:.+]] = call double @differecsum.1(double* %add.ptr, double* %"add.ptr'ipg", i32 %[[sub]])
+; CHECK-NEXT:   %[[dsum2:.+]] = call double @differecsum.1(double* %x, double* %"x'", i32 %div)
+; CHECK-NEXT:   %add = fadd fast double %[[dsum1]], %[[dsum2]]
 ; CHECK-NEXT:   br label %invertentry
 
-; CHECK: invertentry:                                      ; preds = %invertreturn, %if.end3, %invertif.then2
-; CHECK-NEXT:   %toreturn.0 = phi double [ %add, %if.end3 ], [ %retval.0, %invertif.then2 ], [ %retval.0, %invertreturn ]
+; CHECK: invertentry: 
+; CHECK-NEXT:   %toreturn.0 = phi double [ %add, %if.end3 ], [ %[[xload:.+]], %invertif.then2 ], [ 0.000000e+00, %entry ]
 ; CHECK-NEXT:   ret double %toreturn.0
 
-; CHECK: invertif.then2:                                   ; preds = %invertreturn
-; CHECK-NEXT:   %4 = load double, double* %"x'", align 8
-; CHECK-NEXT:   %5 = fadd fast double %4, 1.000000e+00
-; CHECK-NEXT:   store double %5, double* %"x'", align 8
+; CHECK: invertif.then2:
+; CHECK-NEXT:   %[[xload]] = load double, double* %x, align 8, !tbaa !2
+; CHECK-NEXT:   %[[predx:.+]] = load double, double* %"x'", align 8
+; CHECK-NEXT:   %[[postdx:.+]] = fadd fast double %[[predx]], 1.000000e+00
+; CHECK-NEXT:   store double %[[postdx]], double* %"x'", align 8
 ; CHECK-NEXT:   br label %invertentry
-
-; CHECK: invertreturn:                                     ; preds = %entry, %if.then2
-; CHECK-NEXT:   %[[where:.+]] = phi i1 [ true, %if.then2 ], [ false, %entry ]
-; CHECK-NEXT:   %retval.0 = phi double [ %0, %if.then2 ], [ 0.000000e+00, %entry ]
-; CHECK-NEXT:   br i1 %[[where]], label %invertif.then2, label %invertentry
 ; CHECK-NEXT: }