Selective cachereads (#21)

* Enable cache reads by default, which is needed for correctness. 
* Selectively omit caching for reads whose value does not change after the load instruction. Loads that are modified after the load instruction are called "uncacheable" in the code.
* Propagate the uncacheable status of pointer arguments to calls.
* readwriteread C test illustrates behavior of code.

enzyme/Enzyme/Enzyme.cpp

@@ -155,7 +155,8 @@ void HandleAutoDiff(CallInst *CI, TargetLibraryInfo &TLI, AAResults &AA) {//, Lo
 
   bool differentialReturn = cast<Function>(fn)->getReturnType()->isFPOrFPVectorTy();
 
-  auto newFunc = CreatePrimalAndGradient(cast<Function>(fn), constants, TLI, AA, /*should return*/false, differentialReturn, /*topLevel*/true, /*addedType*/nullptr);//, LI, DT);
+  std::set<unsigned> volatile_args;
+  auto newFunc = CreatePrimalAndGradient(cast<Function>(fn), constants, TLI, AA, /*should return*/false, differentialReturn, /*topLevel*/true, /*addedType*/nullptr, volatile_args);//, LI, DT);
 
   if (differentialReturn)
     args.push_back(ConstantFP::get(cast<Function>(fn)->getReturnType(), 1.0));

enzyme/Enzyme/EnzymeLogic.h

@@ -36,6 +36,6 @@ extern llvm::cl::opt<bool> enzyme_print;
 //! return structtype if recursive function
 std::pair<llvm::Function*,llvm::StructType*> CreateAugmentedPrimal(llvm::Function* todiff, llvm::AAResults &AA, const std::set<unsigned>& constant_args, llvm::TargetLibraryInfo &TLI, bool differentialReturn);
 
-llvm::Function* CreatePrimalAndGradient(llvm::Function* todiff, const std::set<unsigned>& constant_args, llvm::TargetLibraryInfo &TLI, llvm::AAResults &AA, bool returnValue, bool differentialReturn, bool topLevel, llvm::Type* additionalArg);
+llvm::Function* CreatePrimalAndGradient(llvm::Function* todiff, const std::set<unsigned>& constant_args, llvm::TargetLibraryInfo &TLI, llvm::AAResults &AA, bool returnValue, bool differentialReturn, bool topLevel, llvm::Type* additionalArg, std::set<unsigned> volatile_args);
 
 #endif

enzyme/Enzyme/FunctionUtils.cpp

@@ -164,8 +164,13 @@ PHINode* canonicalizeIVs(fake::SCEVExpander &e, Type *Ty, Loop *L, DominatorTree
 
 Function* preprocessForClone(Function *F, AAResults &AA, TargetLibraryInfo &TLI) {
  static std::map<Function*,Function*> cache;
- if (cache.find(F) != cache.end()) return cache[F];
-
+ static std::map<Function*, BasicAAResult*> cache_AA;
+ llvm::errs() << "Before cache lookup for " << F->getName() << "\n";
+ if (cache.find(F) != cache.end()) {
+   AA.addAAResult(*(cache_AA[F]));
+   return cache[F];
+ }
+ llvm::errs() << "Did not do cache lookup for " << F->getName() << "\n";
  Function *NewF = Function::Create(F->getFunctionType(), F->getLinkage(), "preprocess_" + F->getName(), F->getParent());
 
  ValueToValueMapTy VMap;
@@ -439,7 +444,7 @@ Function* preprocessForClone(Function *F, AAResults &AA, TargetLibraryInfo &TLI)
     FunctionAnalysisManager AM;
      AM.registerPass([] { return AAManager(); });
      AM.registerPass([] { return ScalarEvolutionAnalysis(); });
-     AM.registerPass([] { return AssumptionAnalysis(); });
+     //AM.registerPass([] { return AssumptionAnalysis(); });
      AM.registerPass([] { return TargetLibraryAnalysis(); });
      AM.registerPass([] { return TargetIRAnalysis(); });
      AM.registerPass([] { return LoopAnalysis(); });
@@ -458,13 +463,22 @@ Function* preprocessForClone(Function *F, AAResults &AA, TargetLibraryInfo &TLI)
      MAM.registerPass([&] { return FunctionAnalysisManagerModuleProxy(AM); });
 
  //Alias analysis is necessary to ensure can query whether we can move a forward pass function
- BasicAA ba;
- auto baa = new BasicAAResult(ba.run(*NewF, AM));
+ //BasicAA ba;
+ //auto baa = new BasicAAResult(ba.run(*NewF, AM));
+ AssumptionCache* AC = new AssumptionCache(*NewF);
+ TargetLibraryInfo* TLI = new TargetLibraryInfo(AM.getResult<TargetLibraryAnalysis>(*NewF));
+ auto baa = new BasicAAResult(NewF->getParent()->getDataLayout(),
+                        *NewF,
+                        *TLI,
+                        *AC,
+                        &AM.getResult<DominatorTreeAnalysis>(*NewF),
+                        AM.getCachedResult<LoopAnalysis>(*NewF),
+                        AM.getCachedResult<PhiValuesAnalysis>(*NewF));
+ cache_AA[F] = baa;
  AA.addAAResult(*baa);
-
- ScopedNoAliasAA sa;
- auto saa = new ScopedNoAliasAAResult(sa.run(*NewF, AM));
- AA.addAAResult(*saa);
+ //ScopedNoAliasAA sa;
+ //auto saa = new ScopedNoAliasAAResult(sa.run(*NewF, AM));
+ //AA.addAAResult(*saa);
 
  }
 

enzyme/Enzyme/GradientUtils.cpp

@@ -351,7 +351,8 @@ Value* GradientUtils::invertPointerM(Value* val, IRBuilder<>& BuilderM) {
       return invertedPointers[val] = cs;
     } else if (auto fn = dyn_cast<Function>(val)) {
       //! Todo allow tape propagation
-      auto newf = CreatePrimalAndGradient(fn, /*constant_args*/{}, TLI, AA, /*returnValue*/false, /*differentialReturn*/fn->getReturnType()->isFPOrFPVectorTy(), /*topLevel*/false, /*additionalArg*/nullptr);
+      std::set<unsigned> uncacheable_args;
+      auto newf = CreatePrimalAndGradient(fn, /*constant_args*/{}, TLI, AA, /*returnValue*/false, /*differentialReturn*/fn->getReturnType()->isFPOrFPVectorTy(), /*topLevel*/false, /*additionalArg*/nullptr, uncacheable_args);
       return BuilderM.CreatePointerCast(newf, fn->getType());
     } else if (auto arg = dyn_cast<CastInst>(val)) {
       auto result = BuilderM.CreateCast(arg->getOpcode(), invertPointerM(arg->getOperand(0), BuilderM), arg->getDestTy(), arg->getName()+"'ipc");
@@ -824,10 +825,12 @@ Value* GradientUtils::lookupM(Value* val, IRBuilder<>& BuilderM) {
         }
     }
 
-    if (!shouldRecompute(inst, available)) {
-        auto op = unwrapM(inst, BuilderM, available, /*lookupIfAble*/true);
-        assert(op);
-        return op;
+    if (!(*(this->can_modref_map))[inst]) {
+      if (!shouldRecompute(inst, available)) {
+          auto op = unwrapM(inst, BuilderM, available, /*lookupIfAble*/true);
+          assert(op);
+          return op;
+      }
     }
     /*
     if (!inLoop) {

enzyme/Enzyme/GradientUtils.h

@@ -89,6 +89,9 @@ class GradientUtils {
   ValueToValueMapTy scopeFrees;
   ValueToValueMapTy originalToNewFn;
 
+  std::map<Instruction*, bool>* can_modref_map;  
+
+
   Value* getNewFromOriginal(Value* originst) {
     assert(originst);
     auto f = originalToNewFn.find(originst);
@@ -507,7 +510,7 @@ class GradientUtils {
             }
             assert(lastScopeAlloc.find(malloc) == lastScopeAlloc.end());
             cast<Instruction>(malloc)->replaceAllUsesWith(ret);
-            auto n = malloc->getName();
+            std::string n = malloc->getName().str();
             erase(cast<Instruction>(malloc));
             ret->setName(n);
         }

enzyme/functional_tests_c/Makefile

@@ -18,7 +18,7 @@ OBJ := $(wildcard *.c)
 
 all: $(patsubst %.c,build/%-enzyme0,$(OBJ)) $(patsubst %.c,build/%-enzyme1,$(OBJ)) $(patsubst %.c,build/%-enzyme2,$(OBJ)) $(patsubst %.c,build/%-enzyme3,$(OBJ))
 
-POST_ENZYME_FLAGS := -mem2reg -sroa -adce -simplifycfg -enzyme_cachereads=true
+POST_ENZYME_FLAGS := -mem2reg -sroa -adce -simplifycfg
 
 #all: $(patsubst %.c,build/%-enzyme1,$(OBJ)) $(patsubst %.c,build/%-enzyme2,$(OBJ)) $(patsubst %.c,build/%-enzyme3,$(OBJ))
 #clean:
@@ -31,7 +31,7 @@ POST_ENZYME_FLAGS := -mem2reg -sroa -adce -simplifycfg -enzyme_cachereads=true
 
 #EXTRA_FLAGS = -indvars -loop-simplify -loop-rotate
 
-# NOTE(TFK): Optimization level 0 is broken right now.
+# /efs/home/tfk/valgrind-3.12.0/vg-in-place
 build/%-enzyme0: %.c
 	@./setup.sh $(CLANG_BIN_PATH)/clang -std=c11 -O1 $(patsubst %.c,%,$<).c -S -emit-llvm -o $@.ll
 	@./setup.sh $(CLANG_BIN_PATH)/opt $@.ll $(EXTRA_FLAGS) -load=$(ENZYME_PLUGIN) -enzyme $(POST_ENZYME_FLAGS) -o $@.bc

enzyme/functional_tests_c/insertsort_sum.c

@@ -16,10 +16,8 @@ float* unsorted_array_init(int N) {
   return arr;
 }
 
-// sums the first half of a sorted array.
-void insertsort_sum (float* array, int N, float* ret) {
+void insertsort_sum (float*__restrict array, int N, float*__restrict ret) {
   float sum = 0;
-  //qsort(array, N, sizeof(float), cmp);
 
   for (int i = 1; i < N; i++) {
     int j = i;
@@ -31,30 +29,16 @@ void insertsort_sum (float* array, int N, float* ret) {
     }
   }
 
-
   for (int i = 0; i < N/2; i++) {
-    printf("Val: %f\n", array[i]);
+    //printf("Val: %f\n", array[i]);
     sum += array[i];
   }
+
   *ret = sum;
 }
 
 
-
-
 int main(int argc, char** argv) {
-
-
-
-  float a = 2.0;
-  float b = 3.0;
-
-
-
-  float da = 0;
-  float db = 0;
-
-
   float ret = 0;
   float dret = 1.0;
 
@@ -71,18 +55,15 @@ int main(int argc, char** argv) {
     printf("%d:%f\n", i, array[i]); 
   }
 
-  //insertsort_sum(array, N, &ret);
+  __builtin_autodiff(insertsort_sum, array, d_array, N, &ret, &dret);
+
+  printf("The total sum is %f\n", ret);
 
   printf("Array after sorting:\n");
   for (int i = 0; i < N; i++) {
     printf("%d:%f\n", i, array[i]); 
   }
 
-
-  printf("The total sum is %f\n", ret);
-
-  __builtin_autodiff(insertsort_sum, array, d_array, N, &ret, &dret);
-
   for (int i = 0; i < N; i++) {
     printf("Diffe for index %d is %f\n", i, d_array[i]);
     if (i%2 == 0) {
@@ -91,13 +72,5 @@ int main(int argc, char** argv) {
       assert(d_array[i] == 1.0);
     }
   }
-
-  //__builtin_autodiff(compute_loops, &a, &da, &b, &db, &ret, &dret);
-
-
-  //assert(da == 100*1.0f);
-  //assert(db == 100*1.0f);
-
-  //printf("hello! %f, res2 %f, da: %f, db: %f\n", ret, ret, da,db);
   return 0;
 }

enzyme/functional_tests_c/insertsort_sum_alt.c

@@ -35,7 +35,7 @@ void insertion_sort_inner(float* array, int i) {
 }
 
 // sums the first half of a sorted array.
-void insertsort_sum (float* array, int N, float* ret) {
+void insertsort_sum (float*__restrict array, int N, float*__restrict ret) {
   float sum = 0;
   //qsort(array, N, sizeof(float), cmp);
 
@@ -45,7 +45,7 @@ void insertsort_sum (float* array, int N, float* ret) {
 
 
   for (int i = 0; i < N/2; i++) {
-    printf("Val: %f\n", array[i]);
+    //printf("Val: %f\n", array[i]);
     sum += array[i];
   }
   *ret = sum;

enzyme/functional_tests_c/readwriteread.c

@@ -0,0 +1,46 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <assert.h>
+#define __builtin_autodiff __enzyme_autodiff
+double __enzyme_autodiff(void*, ...);
+
+double f_read(double* x) {
+  double product = (*x) * (*x);
+  return product;
+}
+
+void g_write(double* x, double product) {
+  *x = (*x) * product;
+}
+
+double h_read(double* x) {
+  return *x;
+}
+
+double readwriteread_helper(double* x) {
+  double product = f_read(x);
+  g_write(x, product);
+  double ret = h_read(x);
+  return ret; 
+}
+
+void readwriteread(double*__restrict x, double*__restrict ret) {
+  *ret = readwriteread_helper(x);
+}
+
+int main(int argc, char** argv) {
+  double ret = 0;
+  double dret = 1.0;
+  double* x = (double*) malloc(sizeof(double));
+  double* dx = (double*) malloc(sizeof(double));
+  *x = 2.0;
+  *dx = 0.0;
+
+  __builtin_autodiff(readwriteread, x, dx, &ret, &dret);
+
+
+  printf("dx is %f ret is %f\n", *dx, ret);
+  assert(*dx == 3*2.0*2.0);
+  return 0;
+}

enzyme/functional_tests_c/setup.sh

@@ -1,8 +1,8 @@
 #!/bin/bash
 
 # NOTE(TFK): Uncomment for local testing.
-export CLANG_BIN_PATH=./../../build-dbg/bin
-export ENZYME_PLUGIN=./../mkdebug/Enzyme/LLVMEnzyme-7.so
+export CLANG_BIN_PATH=./../../llvm/build/bin/
+export ENZYME_PLUGIN=./../build/Enzyme/LLVMEnzyme-7.so
 
 mkdir -p build
 $@

enzyme/functional_tests_c/testfiles/readwriteread-enzyme0.test

@@ -0,0 +1,6 @@
+; RUN: cd %desired_wd
+; RUN: make clean-readwriteread-enzyme0 ENZYME_PLUGIN=%loadEnzyme
+; RUN: make build/readwriteread-enzyme0 ENZYME_PLUGIN=%loadEnzyme CLANG_BIN_PATH=%clangBinPath
+; RUN: build/readwriteread-enzyme0
+; RUN: make clean-readwriteread-enzyme0 ENZYME_PLUGIN=%loadEnzyme
+

enzyme/functional_tests_c/testfiles/readwriteread-enzyme1.test

@@ -0,0 +1,6 @@
+; RUN: cd %desired_wd
+; RUN: make clean-readwriteread-enzyme1 ENZYME_PLUGIN=%loadEnzyme
+; RUN: make build/readwriteread-enzyme1 ENZYME_PLUGIN=%loadEnzyme CLANG_BIN_PATH=%clangBinPath
+; RUN: build/readwriteread-enzyme1
+; RUN: make clean-readwriteread-enzyme1 ENZYME_PLUGIN=%loadEnzyme
+

enzyme/functional_tests_c/testfiles/readwriteread-enzyme2.test

@@ -0,0 +1,6 @@
+; RUN: cd %desired_wd
+; RUN: make clean-readwriteread-enzyme2 ENZYME_PLUGIN=%loadEnzyme
+; RUN: make build/readwriteread-enzyme2 ENZYME_PLUGIN=%loadEnzyme CLANG_BIN_PATH=%clangBinPath
+; RUN: build/readwriteread-enzyme2
+; RUN: make clean-readwriteread-enzyme2 ENZYME_PLUGIN=%loadEnzyme
+

enzyme/functional_tests_c/testfiles/readwriteread-enzyme3.test

@@ -0,0 +1,6 @@
+; RUN: cd %desired_wd
+; RUN: make clean-readwriteread-enzyme3 ENZYME_PLUGIN=%loadEnzyme
+; RUN: make build/readwriteread-enzyme3 ENZYME_PLUGIN=%loadEnzyme CLANG_BIN_PATH=%clangBinPath
+; RUN: build/readwriteread-enzyme3
+; RUN: make clean-readwriteread-enzyme3 ENZYME_PLUGIN=%loadEnzyme
+

enzyme/test/Enzyme/badcall.ll

@@ -42,11 +42,12 @@ attributes #1 = { noinline nounwind uwtable }
 
 ; CHECK: define internal {{(dso_local )?}}{} @diffef(double* nocapture %x, double* %"x'")
 ; CHECK-NEXT: entry:
-; CHECK-NEXT:   %0 = call { { {} } } @augmented_subf(double* %x, double* %"x'")
-; CHECK-NEXT:   store double 2.000000e+00, double* %x, align 8
-; CHECK-NEXT:   store double 0.000000e+00, double* %"x'"
-; CHECK-NEXT:   %1 = call {} @diffesubf(double* nonnull %x, double* %"x'", { {} } undef)
-; CHECK-NEXT:   ret {} undef
+; CHECK-NEXT:	%0 = call { { {}, double } } @augmented_subf(double* %x, double* %"x'")
+; CHECK-NEXT:	%1 = extractvalue { { {}, double } } %0, 0
+; CHECK-NEXT:	store double 2.000000e+00, double* %x, align 8
+; CHECK-NEXT:	store double 0.000000e+00, double* %"x'"
+; CHECK-NEXT:	%2 = call {} @diffesubf(double* nonnull %x, double* %"x'", { {}, double } %1)
+; CHECK-NEXT:	ret {} undef
 ; CHECK-NEXT: }
 
 ; CHECK: define internal {{(dso_local )?}}{ {} } @augmented_metasubf(double* nocapture %x, double* %"x'") 
@@ -56,16 +57,21 @@ attributes #1 = { noinline nounwind uwtable }
 ; CHECK-NEXT:   ret { {} } undef
 ; CHECK-NEXT: }
 
-; CHECK: define internal {{(dso_local )?}}{ { {} } } @augmented_subf(double* nocapture %x, double* %"x'") 
+; CHECK: define internal {{(dso_local )?}}{ { {}, double } } @augmented_subf(double* nocapture %x, double* %"x'") 
 ; CHECK-NEXT: entry:
-; CHECK-NEXT:   %0 = load double, double* %x, align 8
-; CHECK-NEXT:   %mul = fmul fast double %0, 2.000000e+00
-; CHECK-NEXT:   store double %mul, double* %x, align 8
-; CHECK-NEXT:   %1 = call { {} } @augmented_metasubf(double* %x, double* %"x'")
-; CHECK-NEXT:   ret { { {} } } undef
+; CHECK-NEXT:  %0 = alloca { { {}, double } }
+; CHECK-NEXT:  %1 = getelementptr { { {}, double } }, { { {}, double } }* %0, i32 0, i32 0
+; CHECK-NEXT:  %2 = load double, double* %x, align 8
+; CHECK-NEXT:  %3 = getelementptr { {}, double }, { {}, double }* %1, i32 0, i32 1
+; CHECK-NEXT:  store double %2, double* %3
+; CHECK-NEXT:  %mul = fmul fast double %2, 2.000000e+00
+; CHECK-NEXT:  store double %mul, double* %x, align 8
+; CHECK-NEXT:  %4 = call { {} } @augmented_metasubf(double* %x, double* %"x'")
+; CHECK-NEXT:  %5 = load { { {}, double } }, { { {}, double } }* %0
+; CHECK-NEXT:  ret { { {}, double } } %5
 ; CHECK-NEXT: }
 
-; CHECK: define internal {{(dso_local )?}}{} @diffesubf(double* nocapture %x, double* %"x'", { {} } %tapeArg)
+; CHECK: define internal {{(dso_local )?}}{} @diffesubf(double* nocapture %x, double* %"x'", { {}, double } %tapeArg)
 ; CHECK-NEXT: entry:
 ; CHECK-NEXT:   %0 = call {} @diffemetasubf(double* %x, double* %"x'", {} undef)
 ; CHECK-NEXT:   %1 = load double, double* %"x'"