From 767d455188bb578360d8330782b161471997e3c3 Mon Sep 17 00:00:00 2001 From: Martin Liska Date: Wed, 24 Oct 2018 15:52:21 +0200 Subject: [PATCH] Switch conversion: support any ax + b transformation (PR tree-optimization/84436). 2018-10-24 Martin Liska PR tree-optimization/84436 * tree-switch-conversion.c (switch_conversion::contains_same_values_p): Remove. (switch_conversion::contains_linear_function_p): New. (switch_conversion::build_one_array): Support linear transformation on input. * tree-switch-conversion.h (struct switch_conversion): Add contains_linear_function_p declaration. 2018-10-24 Martin Liska PR tree-optimization/84436 * gcc.dg/tree-ssa/pr84436-1.c: New test. * gcc.dg/tree-ssa/pr84436-2.c: New test. * gcc.dg/tree-ssa/pr84436-3.c: New test. * gcc.dg/tree-ssa/pr84436-4.c: New test. * gcc.dg/tree-ssa/pr84436-5.c: New test. From-SVN: r265463 --- gcc/ChangeLog | 11 +++ gcc/testsuite/ChangeLog | 9 +++ gcc/testsuite/gcc.dg/tree-ssa/pr84436-1.c | 36 ++++++++++ gcc/testsuite/gcc.dg/tree-ssa/pr84436-2.c | 67 +++++++++++++++++ gcc/testsuite/gcc.dg/tree-ssa/pr84436-3.c | 24 +++++++ gcc/testsuite/gcc.dg/tree-ssa/pr84436-4.c | 38 ++++++++++ gcc/testsuite/gcc.dg/tree-ssa/pr84436-5.c | 38 ++++++++++ gcc/tree-switch-conversion.c | 87 +++++++++++++++++++---- gcc/tree-switch-conversion.h | 10 +-- 9 files changed, 301 insertions(+), 19 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr84436-1.c create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr84436-2.c create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr84436-3.c create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr84436-4.c create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr84436-5.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 270726a3730..5bb6a54134d 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,14 @@ +2018-10-24 Martin Liska + + PR tree-optimization/84436 + * tree-switch-conversion.c (switch_conversion::contains_same_values_p): + Remove. + (switch_conversion::contains_linear_function_p): New. + (switch_conversion::build_one_array): Support linear + transformation on input. + * tree-switch-conversion.h (struct switch_conversion): Add + contains_linear_function_p declaration. + 2018-10-24 Richard Biener * varasm.c (const_hash_1): Return hash of ADDR_EXPR diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 3a9e5afe9f5..e1679013d08 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,12 @@ +2018-10-24 Martin Liska + + PR tree-optimization/84436 + * gcc.dg/tree-ssa/pr84436-1.c: New test. + * gcc.dg/tree-ssa/pr84436-2.c: New test. + * gcc.dg/tree-ssa/pr84436-3.c: New test. + * gcc.dg/tree-ssa/pr84436-4.c: New test. + * gcc.dg/tree-ssa/pr84436-5.c: New test. + 2018-10-24 Ilya Leoshkevich * gcc.target/s390/20181024-1.c: New test. diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr84436-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr84436-1.c new file mode 100644 index 00000000000..a045b44c2b9 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr84436-1.c @@ -0,0 +1,36 @@ +/* PR tree-optimization/84436 */ +/* { dg-options "-O2 -fdump-tree-switchconv -fdump-tree-optimized" } */ +/* { dg-do run } */ + +int +__attribute__ ((noipa)) +foo (int how) +{ + switch (how) { + case 2: how = 205; break; /* how = 100 * index + 5 */ + case 3: how = 305; break; + case 4: how = 405; break; + case 5: how = 505; break; + case 6: how = 605; break; + } + return how; +} + +int main() +{ + if (foo (2) != 205) + __builtin_abort (); + + if (foo (6) != 605) + __builtin_abort (); + + if (foo (123) != 123) + __builtin_abort (); + + return 0; +} + + +/* { dg-final { scan-tree-dump-times "100 \\*" 1 "switchconv" } } */ +/* { dg-final { scan-tree-dump-times ".* \\+ 5" 1 "switchconv" } } */ +/* { dg-final { scan-tree-dump-not "switch" "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr84436-2.c b/gcc/testsuite/gcc.dg/tree-ssa/pr84436-2.c new file mode 100644 index 00000000000..c34027a08b9 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr84436-2.c @@ -0,0 +1,67 @@ +/* PR tree-optimization/84436 */ +/* { dg-options "-O2 -fdump-tree-switchconv -fdump-tree-optimized" } */ + +char +lowerit(char a) +{ + switch (a) + { + default: + return a; + case 'A': + return 'a'; + case 'B': + return 'b'; + case 'C': + return 'c'; + case 'D': + return 'd'; + case 'E': + return 'e'; + case 'F': + return 'f'; + case 'G': + return 'g'; + case 'H': + return 'h'; + case 'I': + return 'i'; + case 'J': + return 'j'; + case 'K': + return 'k'; + case 'L': + return 'l'; + case 'M': + return 'm'; + case 'N': + return 'n'; + case 'O': + return 'o'; + case 'P': + return 'p'; + case 'Q': + return 'q'; + case 'R': + return 'r'; + case 'S': + return 's'; + case 'T': + return 't'; + case 'U': + return 'u'; + case 'V': + return 'v'; + case 'W': + return 'w'; + case 'X': + return 'x'; + case 'Y': + return 'y'; + case 'Z': + return 'z'; + } +} + +/* { dg-final { scan-tree-dump-times "a_.*\\+ 32" 1 "switchconv" } } */ +/* { dg-final { scan-tree-dump-not "switch" "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr84436-3.c b/gcc/testsuite/gcc.dg/tree-ssa/pr84436-3.c new file mode 100644 index 00000000000..87937f30ab1 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr84436-3.c @@ -0,0 +1,24 @@ +/* PR tree-optimization/84436 */ +/* { dg-options "-O2 -fdump-tree-switchconv -fdump-tree-optimized" } */ + +enum a { b, c, d }; +int e; +void h(enum a); + +void f() { + enum a g; + switch (e) { + case '1': + g = b; + break; + case '2': + g = c; + break; + case '3': + g = d; + } + h(g); +} + +/* { dg-final { scan-tree-dump-times ".* \\+ 4294967247" 1 "switchconv" } } */ +/* { dg-final { scan-tree-dump-not "switch" "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr84436-4.c b/gcc/testsuite/gcc.dg/tree-ssa/pr84436-4.c new file mode 100644 index 00000000000..979250edd1c --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr84436-4.c @@ -0,0 +1,38 @@ +/* PR tree-optimization/84436 */ +/* { dg-options "-O2 -fdump-tree-switchconv -fdump-tree-optimized" } */ +/* { dg-do run } */ + +enum E +{ + A, B, C, +}; + +int +__attribute__ ((noipa)) +foo(enum E e) +{ + switch (e) + { + case A: return 0; + case B: return 1; + case C: return 2; + } + + return -1; +} + +int main() +{ + if (foo (A) != 0) + __builtin_abort (); + + if (foo (B) != 1) + __builtin_abort (); + + if (foo (C) != 2) + __builtin_abort (); + + return 0; +} + +/* { dg-final { scan-tree-dump-not "switch" "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr84436-5.c b/gcc/testsuite/gcc.dg/tree-ssa/pr84436-5.c new file mode 100644 index 00000000000..3f9e2245e84 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr84436-5.c @@ -0,0 +1,38 @@ +/* PR tree-optimization/84436 */ +/* { dg-options "-O2 -fdump-tree-switchconv -fdump-tree-optimized" } */ +/* { dg-do run } */ + +char +__attribute__ ((noipa)) +foo (char how) +{ + switch (how) { + case -4: how = 96; break; + case -3: how = -120; break; + case -2: how = -80; break; + case -1: how = -40; break; + case 0: how = 0; break; + case 1: how = 40; break; + } + return how; +} + +int main() +{ + if (foo (-4) != 96) + __builtin_abort (); + + if (foo (-3) != -120) + __builtin_abort (); + + if (foo (0) != 0) + __builtin_abort (); + + if (foo (123) != 123) + __builtin_abort (); + + return 0; +} + +/* { dg-final { scan-tree-dump-times "40 *\\*" 1 "switchconv" } } */ +/* { dg-final { scan-tree-dump-not "switch" "optimized" } } */ diff --git a/gcc/tree-switch-conversion.c b/gcc/tree-switch-conversion.c index ac2aa585257..e65552edea5 100644 --- a/gcc/tree-switch-conversion.c +++ b/gcc/tree-switch-conversion.c @@ -44,6 +44,7 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA #include "gimplify.h" #include "gimple-iterator.h" #include "gimplify-me.h" +#include "gimple-fold.h" #include "tree-cfg.h" #include "cfgloop.h" #include "alloc-pool.h" @@ -439,25 +440,63 @@ switch_conversion::build_constructors () } } -/* If all values in the constructor vector are the same, return the value. - Otherwise return NULL_TREE. Not supposed to be called for empty - vectors. */ +/* If all values in the constructor vector are products of a linear function + a * x + b, then return true. When true, COEFF_A and COEFF_B and + coefficients of the linear function. Note that equal values are special + case of a linear function with a and b equal to zero. */ -tree -switch_conversion::contains_same_values_p (vec *vec) +bool +switch_conversion::contains_linear_function_p (vec *vec, + wide_int *coeff_a, + wide_int *coeff_b) { unsigned int i; - tree prev = NULL_TREE; constructor_elt *elt; + gcc_assert (vec->length () >= 2); + + /* Let's try to find any linear function a * x + y that can apply to + given values. 'a' can be calculated as follows: + + a = (y2 - y1) / (x2 - x1) where x2 - x1 = 1 (consecutive case indices) + a = y2 - y1 + + and + + b = y2 - a * x2 + + */ + + tree elt0 = (*vec)[0].value; + tree elt1 = (*vec)[1].value; + + if (TREE_CODE (elt0) != INTEGER_CST || TREE_CODE (elt1) != INTEGER_CST) + return false; + + wide_int range_min = wi::to_wide (fold_convert (TREE_TYPE (elt0), + m_range_min)); + wide_int y1 = wi::to_wide (elt0); + wide_int y2 = wi::to_wide (elt1); + wide_int a = y2 - y1; + wide_int b = y2 - a * (range_min + 1); + + /* Verify that all values fulfill the linear function. */ FOR_EACH_VEC_SAFE_ELT (vec, i, elt) { - if (!prev) - prev = elt->value; - else if (!operand_equal_p (elt->value, prev, OEP_ONLY_CONST)) - return NULL_TREE; + if (TREE_CODE (elt->value) != INTEGER_CST) + return false; + + wide_int value = wi::to_wide (elt->value); + if (a * range_min + b != value) + return false; + + ++range_min; } - return prev; + + *coeff_a = a; + *coeff_b = b; + + return true; } /* Return type which should be used for array elements, either TYPE's @@ -551,7 +590,7 @@ void switch_conversion::build_one_array (int num, tree arr_index_type, gphi *phi, tree tidx) { - tree name, cst; + tree name; gimple *load; gimple_stmt_iterator gsi = gsi_for_stmt (m_switch); location_t loc = gimple_location (m_switch); @@ -561,9 +600,27 @@ switch_conversion::build_one_array (int num, tree arr_index_type, name = copy_ssa_name (PHI_RESULT (phi)); m_target_inbound_names[num] = name; - cst = contains_same_values_p (m_constructors[num]); - if (cst) - load = gimple_build_assign (name, cst); + wide_int coeff_a, coeff_b; + bool linear_p = contains_linear_function_p (m_constructors[num], &coeff_a, + &coeff_b); + if (linear_p) + { + if (dump_file && coeff_a.to_uhwi () > 0) + fprintf (dump_file, "Linear transformation with A = %" PRId64 + " and B = %" PRId64 "\n", coeff_a.to_shwi (), + coeff_b.to_shwi ()); + + tree t = unsigned_type_for (TREE_TYPE (m_index_expr)); + gimple_seq seq = NULL; + tree tmp = gimple_convert (&seq, t, m_index_expr); + tree tmp2 = gimple_build (&seq, MULT_EXPR, t, + wide_int_to_tree (t, coeff_a), tmp); + tree tmp3 = gimple_build (&seq, PLUS_EXPR, t, tmp2, + wide_int_to_tree (t, coeff_b)); + tree tmp4 = gimple_convert (&seq, TREE_TYPE (name), tmp3); + gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT); + load = gimple_build_assign (name, tmp4); + } else { tree array_type, ctor, decl, value_type, fetch, default_type; diff --git a/gcc/tree-switch-conversion.h b/gcc/tree-switch-conversion.h index 37ed2193724..ceee75017d9 100644 --- a/gcc/tree-switch-conversion.h +++ b/gcc/tree-switch-conversion.h @@ -733,10 +733,12 @@ struct switch_conversion order of phi nodes. */ void build_constructors (); - /* If all values in the constructor vector are the same, return the value. - Otherwise return NULL_TREE. Not supposed to be called for empty - vectors. */ - tree contains_same_values_p (vec *vec); + /* If all values in the constructor vector are products of a linear function + a * x + b, then return true. When true, COEFF_A and COEFF_B and + coefficients of the linear function. Note that equal values are special + case of a linear function with a and b equal to zero. */ + bool contains_linear_function_p (vec *vec, + wide_int *coeff_a, wide_int *coeff_b); /* Return type which should be used for array elements, either TYPE's main variant or, for integral types, some smaller integral type -- 2.30.2