Remove last uses of canoncial induction variable when scev code generating

We now detect scops without a canonical induction variable and can generate a
polyhedral representation for them. There was no modification necessary to
code generate these scops.

llvm-svn: 177643

polly/lib/Analysis/ScopDetection.cpp

@@ -392,11 +392,14 @@ bool ScopDetection::isValidBasicBlock(BasicBlock &BB,
 }
 
 bool ScopDetection::isValidLoop(Loop *L, DetectionContext &Context) const {
+  if (!SCEVCodegen) {
+    // If code generation is not in scev based mode, we need to ensure that
+    // each loop has a canonical induction variable.
     PHINode *IndVar = L->getCanonicalInductionVariable();
-  // No canonical induction variable.
     if (!IndVar)
-    INVALID(IndVar, "No canonical IV at loop header: "
+      INVALID(IndVar,
-                    << L->getHeader()->getName());
+              "No canonical IV at loop header: " << L->getHeader()->getName());
+  }
 
   // Is the loop count affine?
   const SCEV *LoopCount = SE->getBackedgeTakenCount(L);

polly/lib/Analysis/ScopInfo.cpp

@@ -592,7 +592,7 @@ ScopStmt::ScopStmt(Scop &parent, TempScop &tempScop, const Region &CurRegion,
   // Setup the induction variables.
   for (unsigned i = 0, e = Nest.size(); i < e; ++i) {
     PHINode *PN = Nest[i]->getCanonicalInductionVariable();
-    assert(PN && "Non canonical IV in Scop!");
+    if (PN)
       IVS[i] = PN;
     NestLoops[i] = Nest[i];
   }

polly/test/ScopDetect/base_pointer_in_scop.ll

@@ -1,4 +1,5 @@
 ; RUN: opt %loadPolly -polly-detect -analyze < %s | FileCheck %s
+; RUN: opt %loadPolly -polly-detect -polly-codegen-scev -analyze < %s | FileCheck %s
 
 ; void f(long **A_ptr, long N) {
 ;   long i;

polly/test/ScopDetect/invalidate_scalar_evolution.ll

@@ -0,0 +1,45 @@
+; RUN: opt %loadPolly -polly-detect -analyze < %s | FileCheck %s
+; RUN: opt %loadPolly -polly-detect -analyze -polly-codegen-scev < %s | FileCheck %s -check-prefix=CHECK-SCEV 
+
+; void f(long A[], long N) {
+;   long i;
+;   for (i = 0; i < N; ++i)
+;     A[i] = i;
+; }
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @f(i64* %A, i64 %N, i64 %p) nounwind {
+entry:
+  fence seq_cst
+  br label %pre
+
+pre:
+  %p_tmp = srem i64 %p, 5
+  br i1 true, label %for.i, label %then
+
+for.i:
+  %indvar = phi i64 [ 0, %pre ], [ %indvar.next, %for.i ]
+  %indvar.p1 = phi i64 [ 0, %pre ], [ %indvar.p1.next, %for.i ]
+  %indvar.p2 = phi i64 [ 0, %pre ], [ %indvar.p2.next, %for.i ]
+  %sum = add i64 %indvar, %indvar.p1
+  %sum2 = sub i64 %sum, %indvar.p2
+  %scevgep = getelementptr i64* %A, i64 %indvar
+  store i64 %indvar, i64* %scevgep
+  %indvar.next = add nsw i64 %indvar, 1
+  %indvar.p1.next = add nsw i64 %indvar.p1, %p_tmp
+  %indvar.p2.next = add nsw i64 %indvar.p2, %p_tmp
+  %exitcond = icmp eq i64 %sum2, %N
+  br i1 %exitcond, label %then, label %for.i
+
+then:
+  br label %return
+
+return:
+  fence seq_cst
+  ret void
+}
+
+; CHECK-NOT: Valid Region for Scop
+; CHECK-SCEV: Valid Region for Scop: for.i => then

polly/test/ScopDetect/simple_loop.ll

@@ -1,4 +1,5 @@
 ; RUN: opt %loadPolly -polly-detect -analyze < %s | FileCheck %s
+; RUN: opt %loadPolly -polly-detect -polly-codegen-scev -analyze < %s | FileCheck %s
 
 ; void f(long A[], long N) {
 ;   long i;

polly/test/ScopDetect/simple_loop_non_single_entry.ll

@@ -1,5 +1,7 @@
 ; RUN: opt %loadPolly -polly-detect -analyze < %s | FileCheck %s
 ; RUN: opt %loadPolly -polly-region-simplify -polly-detect -analyze < %s | FileCheck %s -check-prefix=CHECK-SIMPLIFY
+; RUN: opt %loadPolly -polly-detect -polly-codegen-scev -analyze < %s | FileCheck %s
+; RUN: opt %loadPolly -polly-region-simplify -polly-detect -polly-codegen-scev -analyze < %s | FileCheck %s -check-prefix=CHECK-SIMPLIFY
 
 ; void f(long A[], long N) {
 ;   long i;

polly/test/ScopDetect/simple_loop_non_single_exit.ll

@@ -1,5 +1,7 @@
 ; RUN: opt %loadPolly -polly-detect -analyze < %s | FileCheck %s
 ; RUN: opt %loadPolly -polly-region-simplify -polly-detect -analyze < %s | FileCheck %s -check-prefix=CHECK-SIMPLIFY
+; RUN: opt %loadPolly -polly-detect -polly-codegen-scev -analyze < %s | FileCheck %s
+; RUN: opt %loadPolly -polly-region-simplify -polly-detect -polly-codegen-scev -analyze < %s | FileCheck %s -check-prefix=CHECK-SIMPLIFY
 
 ; void f(long A[], long N) {
 ;   long i;

polly/test/ScopDetect/simple_loop_non_single_exit_2.ll

@@ -1,5 +1,7 @@
 ; RUN: opt %loadPolly -polly-detect -analyze < %s | FileCheck %s
 ; RUN: opt %loadPolly -polly-region-simplify -polly-detect -analyze < %s | FileCheck %s -check-prefix=CHECK-SIMPLIFY
+; RUN: opt %loadPolly -polly-detect -polly-codegen-scev -analyze < %s | FileCheck %s
+; RUN: opt %loadPolly -polly-region-simplify -polly-detect -polly-codegen-scev -analyze < %s | FileCheck %s -check-prefix=CHECK-SIMPLIFY
 
 ; void f(long A[], long N) {
 ;   long i;

polly/test/ScopDetect/simple_loop_two_phi_nodes.ll

@@ -1,4 +1,5 @@
 ; RUN: opt %loadPolly -polly-detect -analyze < %s | FileCheck %s
+; RUN: opt %loadPolly -polly-detect -polly-codegen-scev -analyze < %s | FileCheck %s -check-prefix=CHECK-SCEV
 
 ; void f(long A[], long N) {
 ;   long i;
@@ -32,3 +33,4 @@ return:
 }
 
 ; CHECK-NOT: Valid Region for Scop
+; CHECK-SCEV: Valid Region for Scop: for.i => return

polly/test/ScopDetect/simple_loop_with_param_2.ll

@@ -1,4 +1,5 @@
 ; RUN: opt %loadPolly -basicaa -polly-detect -analyze < %s | FileCheck %s
+; RUN: opt %loadPolly -basicaa -polly-detect -polly-codegen-scev -analyze < %s | FileCheck %s
 
 ; void f(long A[], int N, int *init_ptr) {
 ;   long i, j;

polly/test/polybench/datamining/covariance/covariance_without_param.ll

@@ -1,6 +1,4 @@
-; RUN: opt %loadPolly  %defaultOpts -polly-detect -polly-ast -analyze  %s | FileCheck %s
+; RUN: opt %loadPolly  %defaultOpts -polly-detect -polly-ast -polly-codegen-scev -analyze  %s | FileCheck %s
-; region-simplify make polly fail to detect the canonical induction variable.
-; XFAIL:*
 
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
 target triple = "x86_64-unknown-linux-gnu"

polly/test/polybench/linear-algebra/solvers/lu/lu_with_param.ll

@@ -1,6 +1,4 @@
-; RUN: opt %loadPolly  %defaultOpts -polly-detect -analyze  %s | FileCheck %s
+; RUN: opt %loadPolly  %defaultOpts -polly-detect -polly-codegen-scev -analyze  %s | FileCheck %s
-; region-simplify make polly fail to detect the canonical induction variable.
-; XFAIL:*
 
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
 target triple = "x86_64-unknown-linux-gnu"