[Polly] Make optimizations based on pattern matching be enabled by default

[gareevroman]

Summary

Currently, pattern based optimizations of Polly can identify matrix multiplication and optimize it according to BLIS matmul optimization pattern (see ScheduleTreeOptimizer for details). This patch makes optimizations based on pattern matching be enabled by default.

[grosser]

LGTM.

lib/Transform/ScheduleOptimizer.cpp

RegisterTileSizes("polly-register-tile-sizes",
                       cl::desc("A tile size for each loop dimension, filled "
                                "with --polly-register-tile-size"),
                       cl::Hidden, cl::ZeroOrMore, cl::CommaSeparated,
                       cl::cat(PollyCategory));
 
 static cl::opt<bool>
     PMBasedOpts("polly-pattern-matching-based-opts",
                 cl::desc("Perform optimizations based on pattern matching"),
-                cl::init(false), cl::ZeroOrMore, cl::cat(PollyCategory));
+                cl::init(true), cl::ZeroOrMore, cl::cat(PollyCategory));
 
 static cl::opt<bool> OptimizedScops(
     "polly-optimized-scops",
     cl::desc("Polly - Dump polyhedral description of Scops optimized with "
              "the isl scheduling optimizer and the set of post-scheduling "
              "transformations is applied on the schedule tree"),
     cl::init(false), cl::ZeroOrMore, cl::cat(PollyCategory));
 

test/ScheduleOptimizer/full_partial_tile_separation.ll

-; RUN: opt -S %loadPolly -polly-vectorizer=stripmine -polly-opt-isl -polly-ast -analyze < %s | FileCheck %s
+; RUN: opt -S %loadPolly -polly-pattern-matching-based-opts=false \
+; RUN: -polly-vectorizer=stripmine -polly-opt-isl -polly-ast -analyze \
+; RUN: < %s | FileCheck %s
 ; CHECK:          // 1st level tiling - Tiles
 ; CHECK-NEXT:    #pragma known-parallel
 ; CHECK-NEXT:    for (int c0 = 0; c0 <= floord(ni - 1, 32); c0 += 1)
 ; CHECK-NEXT:      for (int c1 = 0; c1 <= floord(nj - 1, 32); c1 += 1)
 ; CHECK-NEXT:        for (int c2 = 0; c2 <= floord(nk - 1, 32); c2 += 1) {
 ; CHECK-NEXT:          // 1st level tiling - Points
 ; CHECK-NEXT:          for (int c3 = 0; c3 <= min(31, ni - 32 * c0 - 1); c3 += 1) {
 ; CHECK-NEXT:            for (int c4 = 0; c4 <= min(7, -8 * c1 + nj / 4 - 1); c4 += 1)

test/ScheduleOptimizer/pattern-matching-based-opts.ll

-; RUN: opt %loadPolly -polly-opt-isl -debug < %s 2>&1| FileCheck %s
+; RUN: opt %loadPolly -polly-opt-isl -polly-pattern-matching-based-opts=false \
+; RUN: -debug < %s 2>&1| FileCheck %s
 ; RUN: opt %loadPolly -polly-opt-isl -polly-pattern-matching-based-opts=true -debug < %s 2>&1| FileCheck %s --check-prefix=PATTERN-MATCHING-OPTS
 ; REQUIRES: asserts
 ;
 ;    /* C := alpha*A*B + beta*C */
 ;    for (i = 0; i < _PB_NI; i++)
 ;      for (j = 0; j < _PB_NJ; j++)
 ;        {
 ;    C[i][j] *= beta;

test/ScheduleOptimizer/prevectorization-without-tiling.ll

-; RUN: opt -S %loadPolly -basicaa -polly-opt-isl -polly-tiling=false -polly-vectorizer=polly -polly-ast -analyze < %s | FileCheck %s
+; RUN: opt -S %loadPolly -basicaa -polly-opt-isl -polly-tiling=false \
+; RUN: -polly-pattern-matching-based-opts=false -polly-vectorizer=polly \
+; RUN: -polly-ast -analyze < %s | FileCheck %s
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
 @C = common global [1536 x [1536 x float]] zeroinitializer, align 16
 @A = common global [1536 x [1536 x float]] zeroinitializer, align 16
 @B = common global [1536 x [1536 x float]] zeroinitializer, align 16
 
 ; Function Attrs: nounwind uwtable
 define void @foo() #0 {

test/ScheduleOptimizer/prevectorization.ll

-; RUN: opt -S %loadPolly -basicaa -polly-opt-isl -polly-vectorizer=polly -polly-ast -analyze < %s | FileCheck %s 
-; RUN: opt -S %loadPolly -basicaa -polly-opt-isl -polly-vectorizer=stripmine -polly-ast -analyze < %s | FileCheck %s
+; RUN: opt -S %loadPolly -basicaa -polly-opt-isl \
+; RUN: -polly-pattern-matching-based-opts=false -polly-vectorizer=polly \
+; RUN: -polly-ast -analyze < %s | FileCheck %s 
+; RUN: opt -S %loadPolly -basicaa -polly-opt-isl \
+; RUN: -polly-pattern-matching-based-opts=false -polly-vectorizer=stripmine \
+; RUN: -polly-ast -analyze < %s | FileCheck %s
 
 ; RUN: opt -S %loadPolly -basicaa -polly-opt-isl \
-; RUN:                   -polly-vectorizer=polly -polly-ast -analyze \
-; RUN:                   -polly-prevect-width=16 < %s | \
-; RUN:                   FileCheck %s -check-prefix=VEC16
+; RUN: -polly-vectorizer=polly -polly-pattern-matching-based-opts=false \
+; RUN: -polly-ast -analyze -polly-prevect-width=16 < %s | \
+; RUN: FileCheck %s -check-prefix=VEC16
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
 @C = common global [1536 x [1536 x float]] zeroinitializer, align 16
 @A = common global [1536 x [1536 x float]] zeroinitializer, align 16
 @B = common global [1536 x [1536 x float]] zeroinitializer, align 16
 
 ; Function Attrs: nounwind uwtable