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author | Richard Guenther <rguenther@suse.de> | 2012-07-04 12:10:40 +0000 |
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committer | Richard Biener <rguenth@gcc.gnu.org> | 2012-07-04 12:10:40 +0000 |
commit | 6c9df5a0014040115ebe576c4c0b7914a0414422 (patch) | |
tree | 5351f6868c854e291586eee626ce32773354d355 | |
parent | e1b6bbea37bb9e0dfaba80f5d7483fcd7ac9baa6 (diff) | |
download | gcc-6c9df5a0014040115ebe576c4c0b7914a0414422.zip gcc-6c9df5a0014040115ebe576c4c0b7914a0414422.tar.gz gcc-6c9df5a0014040115ebe576c4c0b7914a0414422.tar.bz2 |
re PR middle-end/53844 (GCC generates suboptimal code for unused members of classes in some cases on multiple targets.)
2012-07-04 Richard Guenther <rguenther@suse.de>
PR tree-optimization/53844
* tree-ssa-dse.c (dse_possible_dead_store_p): Properly handle
the loop virtual PHI.
* g++.dg/tree-ssa/pr53844.C: New testcase.
From-SVN: r189256
-rw-r--r-- | gcc/ChangeLog | 6 | ||||
-rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/tree-ssa/pr53844.C | 78 | ||||
-rw-r--r-- | gcc/tree-ssa-dse.c | 12 |
4 files changed, 99 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 27c8cfc..c33c5a5 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,11 @@ 2012-07-04 Richard Guenther <rguenther@suse.de> + PR tree-optimization/53844 + * tree-ssa-dse.c (dse_possible_dead_store_p): Properly handle + the loop virtual PHI. + +2012-07-04 Richard Guenther <rguenther@suse.de> + PR tree-optimization/53849 * tree-cfg.c (move_stmt_op): Only call add_referenced_var for duplicated locals. Use add_referenced_var_1 to avoid diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 884f66b..3d1fda9 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,5 +1,10 @@ 2012-07-04 Richard Guenther <rguenther@suse.de> + PR tree-optimization/53844 + * g++.dg/tree-ssa/pr53844.C: New testcase. + +2012-07-04 Richard Guenther <rguenther@suse.de> + PR tree-optimization/53849 * gcc.dg/pr53849.c: New testcase. diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr53844.C b/gcc/testsuite/g++.dg/tree-ssa/pr53844.C new file mode 100644 index 0000000..0be29d8 --- /dev/null +++ b/gcc/testsuite/g++.dg/tree-ssa/pr53844.C @@ -0,0 +1,78 @@ +// { dg-do compile } +// { dg-options "-O2 -fdump-tree-optimized-vops" } + +struct VBase; + +//Very minimal numeric vector class where Base provides the policy +template<typename Base=VBase> +struct Vector : public Base{ + + inline Vector(const Base& b) + :Base(b) + { + } + + //Assignment from any other sort of Vector + template<typename Base2> + void operator= (const Vector<Base2>& from) + { + for(int i=0; i<100; i++){ + (*this)[i]=from[i]; + } + } +}; + + +//Base class to represent pointer as a Vector +struct VBase{ + double * const my_data; + + double& operator[](int i) { + return my_data[i]; + } + + const double& operator[](int i) const { + return my_data[i]; + } +}; + +//Base class providing very minimalistic expression template +template<class B2> struct ScalarMulExpr +{ + const int& mul; + const Vector<B2>& vec; + + int size() const + { + return vec.size(); + } + + double operator[](int i) const + { + return vec[i]*mul; + } + + ScalarMulExpr(const Vector<B2>& vec_, const int& m) + :mul(m),vec(vec_) + { + } +}; + +//Allow vector to be multiplied by a scalar +template<class B2> +Vector<ScalarMulExpr<B2> > operator*(const Vector<B2>& lhs, const int& rhs) +{ + return ScalarMulExpr<B2>(lhs, rhs); +} + +//Test function producing suboptimal asm code +void test(const Vector<>& in, Vector<>& out, int i) +{ + out=in*1*1*1*1*1*1*1*1*1*1*1; +} + +// There should be a single store remaining, inside the loops. All +// dead stores to unused temporaries should have been removed. + +// { dg-final { scan-tree-dump-times "VDEF" 1 "optimized" } } +// { dg-final { cleanup-tree-dump "optimized" } } diff --git a/gcc/tree-ssa-dse.c b/gcc/tree-ssa-dse.c index 5fdba8c..04cc6ad 100644 --- a/gcc/tree-ssa-dse.c +++ b/gcc/tree-ssa-dse.c @@ -94,7 +94,7 @@ dse_possible_dead_store_p (gimple stmt, gimple *use_stmt) temp = stmt; do { - gimple use_stmt; + gimple use_stmt, defvar_def; imm_use_iterator ui; bool fail = false; tree defvar; @@ -108,6 +108,7 @@ dse_possible_dead_store_p (gimple stmt, gimple *use_stmt) defvar = PHI_RESULT (temp); else defvar = gimple_vdef (temp); + defvar_def = temp; temp = NULL; FOR_EACH_IMM_USE_STMT (use_stmt, ui, defvar) { @@ -139,7 +140,14 @@ dse_possible_dead_store_p (gimple stmt, gimple *use_stmt) fail = true; BREAK_FROM_IMM_USE_STMT (ui); } - temp = use_stmt; + /* Do not consider the PHI as use if it dominates the + stmt defining the virtual operand we are processing, + we have processed it already in this case. */ + if (gimple_bb (defvar_def) != gimple_bb (use_stmt) + && !dominated_by_p (CDI_DOMINATORS, + gimple_bb (defvar_def), + gimple_bb (use_stmt))) + temp = use_stmt; } /* If the statement is a use the store is not dead. */ else if (ref_maybe_used_by_stmt_p (use_stmt, |