> > } > > + else if (EDGE_SUCC (bb1, 0)->dest == EDGE_SUCC (bb2, 0)->dest > > + && single_succ_p (bb1) > > + && single_succ_p (bb2) > > + && single_pred_p (bb1) > > + && single_pred_p (bb2) > > + && single_succ_p (EDGE_SUCC (bb1, 0)->dest)) > > please do the single_succ/pred checks below where appropriate, also what's > the last check about? Done. > why does the merge block need a single successor? I was using it to fix an ICE, but I realize that's not the right fix. I'm now checking If the BB is empty instead, in which case it's just a fall through edge so don't treat it as a diamond. > > > + { > > + gimple_stmt_iterator it1 = gsi_start_nondebug_after_labels_bb > (bb1); > > + gimple_stmt_iterator it2 = gsi_start_nondebug_after_labels_bb > (bb2); > > + if (gsi_one_before_end_p (it1) && gsi_one_before_end_p (it2)) > > + { > > + gimple *stmt1 = gsi_stmt (it1); > > + gimple *stmt2 = gsi_stmt (it2); > > + if (is_gimple_assign (stmt1) && is_gimple_assign (stmt2)) > > + { > > + enum tree_code code1 = gimple_assign_rhs_code (stmt1); > > + enum tree_code code2 = gimple_assign_rhs_code (stmt2); > > + diamond_minmax_p > > + = (code1 == MIN_EXPR || code1 == MAX_EXPR) > > + && (code2 == MIN_EXPR || code2 == MAX_EXPR); > > + } > > + } > > + } > > I'd generalize this to general diamond detection, simply cutting off > *_replacement workers that do not handle diamonds and do appropriate > checks in minmax_replacement only. > Done. > > else > > continue; > > > > @@ -316,6 +340,13 @@ tree_ssa_phiopt_worker (bool do_store_elim, > bool do_hoist_loads, bool early_p) > > if (!candorest) > > continue; > > > > + /* Check that we're looking for nested phis. */ > > + if (phis == NULL && diamond_minmax_p) > > + { > > + phis = phi_nodes (EDGE_SUCC (bb2, 0)->dest); > > + e2 = EDGE_SUCC (bb2, 0); > > + } > > + > > instead > > basic_block merge = diamond_p ? EDGE_SUCC (bb2, 0)->dest : bb2; > gimple_seq phis = phi_nodes (merge); > Done. > > > phi = single_non_singleton_phi_for_edges (phis, e1, e2); > > if (!phi) > > continue; > > @@ -329,6 +360,7 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool > > do_hoist_loads, bool early_p) > > > > gphi *newphi; > > if (single_pred_p (bb1) > > + && !diamond_minmax_p > > && (newphi = factor_out_conditional_conversion (e1, e2, phi, > > arg0, arg1, > > cond_stmt))) > > @@ -343,20 +375,25 @@ tree_ssa_phiopt_worker (bool do_store_elim, > bool do_hoist_loads, bool early_p) > > } > > > > /* Do the replacement of conditional if it can be done. */ > > - if (!early_p && two_value_replacement (bb, bb1, e2, phi, arg0, > arg1)) > > + if (!early_p > > + && !diamond_minmax_p > > + && two_value_replacement (bb, bb1, e2, phi, arg0, arg1)) > > cfgchanged = true; > > - else if (match_simplify_replacement (bb, bb1, e1, e2, phi, > > - arg0, arg1, > > - early_p)) > > + else if (!diamond_minmax_p > > + && match_simplify_replacement (bb, bb1, e1, e2, phi, > > + arg0, arg1, early_p)) > > cfgchanged = true; > > else if (!early_p > > + && !diamond_minmax_p > > && single_pred_p (bb1) > > && cond_removal_in_builtin_zero_pattern (bb, bb1, e1, > e2, > > phi, arg0, arg1)) > > cfgchanged = true; > > - else if (minmax_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) > > + else if (minmax_replacement (bb, bb1, bb2, e1, e2, phi, arg0, arg1, > > + diamond_minmax_p)) > > cfgchanged = true; > > else if (single_pred_p (bb1) > > + && !diamond_minmax_p > > && spaceship_replacement (bb, bb1, e1, e2, phi, arg0, > arg1)) > > cfgchanged = true; > > } > > @@ -385,7 +422,7 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool > > do_hoist_loads, bool early_p) > > > > static void > > replace_phi_edge_with_variable (basic_block cond_block, > > - edge e, gphi *phi, tree new_tree) > > + edge e, gphi *phi, tree new_tree, bool > delete_bb = true) > > { > > basic_block bb = gimple_bb (phi); > > gimple_stmt_iterator gsi; > > @@ -428,7 +465,7 @@ replace_phi_edge_with_variable (basic_block > cond_block, > > edge_to_remove = EDGE_SUCC (cond_block, 1); > > else > > edge_to_remove = EDGE_SUCC (cond_block, 0); > > - if (EDGE_COUNT (edge_to_remove->dest->preds) == 1) > > + if (EDGE_COUNT (edge_to_remove->dest->preds) == 1 && delete_bb) > > why do you need this change? When this function replaces the edge it doesn't seem to update the dominators. Since It's replacing the middle BB we then end up with an error gcc/testsuite/gcc.dg/tree-ssa/minmax-14.c:17:1: error: dominator of 5 should be 4, not 2 during early verify. So instead, I replace the BB but defer its deletion until cleanup which removes it and updates the dominators. > > Did you check whether the new case works when the merge block has more > than two incoming edges? > Yes, added a new testcase for it. > > + else if (middle_bb != alt_middle_bb && threeway_p) > > + { > > + /* Recognize the following case: > > + > > + if (smaller < larger) > > + a = MIN (smaller, c); > > + else > > + b = MIN (larger, c); > > + x = PHI > > + > > + This is equivalent to > > + > > + a = MIN (smaller, c); > > + x = MIN (larger, a); */ > > + > > + gimple *assign = last_and_only_stmt (middle_bb); > > + tree lhs, op0, op1, bound; > > + tree alt_lhs, alt_op0, alt_op1; > > + bool invert = false; > > + > > + if (!single_pred_p (middle_bb) > > + || !single_pred_p (alt_middle_bb)) > > + return false; > > + > > + if (!assign > > + || gimple_code (assign) != GIMPLE_ASSIGN) > > + return false; > > + > > + lhs = gimple_assign_lhs (assign); > > + ass_code = gimple_assign_rhs_code (assign); > > + if (ass_code != MAX_EXPR && ass_code != MIN_EXPR) > > + return false; > > + > > + op0 = gimple_assign_rhs1 (assign); > > + op1 = gimple_assign_rhs2 (assign); > > + > > + assign = last_and_only_stmt (alt_middle_bb); > > + if (!assign > > + || gimple_code (assign) != GIMPLE_ASSIGN) > > + return false; > > + > > + alt_lhs = gimple_assign_lhs (assign); > > + if (ass_code != gimple_assign_rhs_code (assign)) > > + return false; > > + > > + alt_op0 = gimple_assign_rhs1 (assign); > > + alt_op1 = gimple_assign_rhs2 (assign); > > + > > + if (!operand_equal_for_phi_arg_p (lhs, arg_true) > > + || !operand_equal_for_phi_arg_p (alt_lhs, arg_false)) > > + return false; > > + > > + if ((operand_equal_for_phi_arg_p (op0, smaller) > > + || (alt_smaller > > + && operand_equal_for_phi_arg_p (op0, alt_smaller))) > > + && (operand_equal_for_phi_arg_p (alt_op0, larger) > > + || (alt_larger > > + && operand_equal_for_phi_arg_p (alt_op0, alt_larger)))) > > + { > > + /* We got here if the condition is true, i.e., SMALLER < LARGER. */ > > + if (!operand_equal_for_phi_arg_p (op1, alt_op1)) > > + return false; > > + > > + if ((arg0 = strip_bit_not (op0)) != NULL > > + && (arg1 = strip_bit_not (alt_op0)) != NULL > > + && (bound = strip_bit_not (op1)) != NULL) > > + { > > + minmax = MAX_EXPR; > > + ass_code = invert_minmax_code (ass_code); > > + invert = true; > > + } > > + else > > + { > > + bound = op1; > > + minmax = MIN_EXPR; > > + arg0 = op0; > > + arg1 = alt_op0; > > + } > > + } > > + else if ((operand_equal_for_phi_arg_p (op0, larger) > > + || (alt_larger > > + && operand_equal_for_phi_arg_p (op0, alt_larger))) > > + && (operand_equal_for_phi_arg_p (alt_op0, smaller) > > + || (alt_smaller > > + && operand_equal_for_phi_arg_p (alt_op0, > alt_smaller)))) > > + { > > + /* We got here if the condition is true, i.e., SMALLER > LARGER. */ > > + if (!operand_equal_for_phi_arg_p (op1, alt_op1)) > > + return false; > > + > > + if ((arg0 = strip_bit_not (op0)) != NULL > > + && (arg1 = strip_bit_not (alt_op0)) != NULL > > + && (bound = strip_bit_not (op1)) != NULL) > > + { > > + minmax = MIN_EXPR; > > + ass_code = invert_minmax_code (ass_code); > > + invert = true; > > + } > > + else > > + { > > + bound = op1; > > + minmax = MAX_EXPR; > > + arg0 = op0; > > + arg1 = alt_op0; > > + } > > + } > > + else > > + return false; > > Did you check you have coverage for all cases above in your testcases? I've added some more, should now have full coverage. > > > + /* Reset any range information from the basic block. */ > > + reset_flow_sensitive_info_in_bb (cond_bb); > > Huh. You need to reset flow-sensitive info of the middle-bb stmt that > prevails only... > > > + /* Emit the statement to compute min/max. */ > > + gimple_seq stmts = NULL; > > + tree phi_result = PHI_RESULT (phi); > > + result = gimple_build (&stmts, minmax, TREE_TYPE (phi_result), arg0, > bound); > > + result = gimple_build (&stmts, ass_code, TREE_TYPE > > + (phi_result), result, arg1); > > ... but you are re-building both here. And also you drop locations, the > preserved min/max should keep the old, the new should get the location of > ... hmm, the condition possibly? Done, also added a testcase which checks that it still works when -g. Bootstrapped Regtested on aarch64-none-linux-gnu and no issues. Ok for master? Thanks, Tamar gcc/ChangeLog: * tree-ssa-phiopt.cc (minmax_replacement): Optionally search for the phi sequence of a three-way conditional. (replace_phi_edge_with_variable): Support deferring of BB removal. (tree_ssa_phiopt_worker): Detect diamond phi structure for three-way min/max. (strip_bit_not, invert_minmax_code): New. gcc/testsuite/ChangeLog: * gcc.dg/tree-ssa/split-path-1.c: Disable phi-opts so we don't optimize code away. * gcc.dg/tree-ssa/minmax-10.c: New test. * gcc.dg/tree-ssa/minmax-11.c: New test. * gcc.dg/tree-ssa/minmax-12.c: New test. * gcc.dg/tree-ssa/minmax-13.c: New test. * gcc.dg/tree-ssa/minmax-14.c: New test. * gcc.dg/tree-ssa/minmax-15.c: New test. * gcc.dg/tree-ssa/minmax-16.c: New test. * gcc.dg/tree-ssa/minmax-3.c: New test. * gcc.dg/tree-ssa/minmax-4.c: New test. * gcc.dg/tree-ssa/minmax-5.c: New test. * gcc.dg/tree-ssa/minmax-6.c: New test. * gcc.dg/tree-ssa/minmax-7.c: New test. * gcc.dg/tree-ssa/minmax-8.c: New test. * gcc.dg/tree-ssa/minmax-9.c: New test. --- inline copy of patch --- diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-10.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-10.c new file mode 100644 index 0000000000000000000000000000000000000000..589953684416a9d263084deb58f6cde7094dd517 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-10.c @@ -0,0 +1,20 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-optimized" } */ + +#include + +uint8_t three_max (uint8_t xc, uint8_t xm, uint8_t xy) { + uint8_t xk; + xc=~xc; + xm=~xm; + xy=~xy; + if (xc > xm) { + xk = (uint8_t) (xc > xy ? xc : xy); + } else { + xk = (uint8_t) (xm > xy ? xm : xy); + } + return xk; +} + +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 2 "optimized" } } */ +/* { dg-final { scan-tree-dump-times "= ~" 1 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-11.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-11.c new file mode 100644 index 0000000000000000000000000000000000000000..1c2ef01b5d1e639fbf95bb5ca473b63cc98e9df1 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-11.c @@ -0,0 +1,21 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-optimized" } */ + +#include + +uint8_t three_minmax1 (uint8_t xc, uint8_t xm, uint8_t xy) { + uint8_t xk; + xc=~xc; + xm=~xm; + xy=~xy; + if (xc > xm) { + xk = (uint8_t) (xc < xy ? xc : xy); + } else { + xk = (uint8_t) (xm < xy ? xm : xy); + } + return xk; +} + +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 1 "optimized" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 1 "optimized" } } */ +/* { dg-final { scan-tree-dump-times "= ~" 1 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-12.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-12.c new file mode 100644 index 0000000000000000000000000000000000000000..3d0c07d9b57dd689bcb89653937727ab441e7f2b --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-12.c @@ -0,0 +1,20 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-phiopt" } */ + +#include + +uint8_t three_minmax3 (uint8_t xc, uint8_t xm, uint8_t xy) { + uint8_t xk; + xc=~xc; + xm=~xm; + xy=~xy; + if (xc > xm) { + xk = (uint8_t) (xy < xc ? xc : xy); + } else { + xk = (uint8_t) (xm < xy ? xm : xy); + } + return xk; +} + +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 1 "phiopt1" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 1 "phiopt1" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-13.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-13.c new file mode 100644 index 0000000000000000000000000000000000000000..c0d0f27c8027ae87654532d1b919cfeccf4413e0 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-13.c @@ -0,0 +1,19 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-phiopt" } */ + +#include + +uint8_t three_minmax2 (uint8_t xc, uint8_t xm, uint8_t xy) { + uint8_t xk; + xc=~xc; + xm=~xm; + xy=~xy; + if (xc > xm) { + xk = (uint8_t) (xc > xy ? xc : xy); + } else { + xk = (uint8_t) (xm < xy ? xm : xy); + } + return xk; +} +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 1 "phiopt1" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 1 "phiopt1" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-14.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-14.c new file mode 100644 index 0000000000000000000000000000000000000000..9c0cadbf7e3119527cb2007d01fe4c7dd772c069 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-14.c @@ -0,0 +1,21 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-optimized" } */ + +#include + +uint8_t three_minmax11 (uint8_t xc, uint8_t xm, uint8_t xy) { + uint8_t xk; + xc=~xc; + xm=~xm; + xy=~xy; + if (xc < xm) { + xk = (uint8_t) (xc > xy ? xc : xy); + } else { + xk = (uint8_t) (xm > xy ? xm : xy); + } + return xk; +} + +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 1 "optimized" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 1 "optimized" } } */ +/* { dg-final { scan-tree-dump-times "= ~" 1 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-15.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-15.c new file mode 100644 index 0000000000000000000000000000000000000000..1d97a16564f069b4348ff325c4fd713a224f838a --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-15.c @@ -0,0 +1,21 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-phiopt" } */ + +#include +#include + +uint8_t three_min (uint8_t xc, uint8_t xm, uint8_t xy, bool m) { + uint8_t xk; + if (xc) + { + if (xc < xm) { + xk = (uint8_t) (xc < xy ? xc : xy); + } else { + xk = (uint8_t) (xm < xy ? xm : xy); + } + } + + return xk; +} +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 3 "phiopt1" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 0 "phiopt1" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-16.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-16.c new file mode 100644 index 0000000000000000000000000000000000000000..89377a2cb341bdafa6ba145c61c1f966af536839 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-16.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-phiopt -g" } */ + +#include + +uint8_t three_min (uint8_t xc, uint8_t xm, uint8_t xy) { + uint8_t xk; + if (xc < xm) { + xk = (uint8_t) (xc < xy ? xc : xy); + } else { + xk = (uint8_t) (xm < xy ? xm : xy); + } + return xk; +} + +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 3 "phiopt1" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 0 "phiopt1" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-3.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-3.c new file mode 100644 index 0000000000000000000000000000000000000000..de3b2e946e81701e3b75f580e6a843695a05786e --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-3.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-phiopt" } */ + +#include + +uint8_t three_min (uint8_t xc, uint8_t xm, uint8_t xy) { + uint8_t xk; + if (xc < xm) { + xk = (uint8_t) (xc < xy ? xc : xy); + } else { + xk = (uint8_t) (xm < xy ? xm : xy); + } + return xk; +} + +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 3 "phiopt1" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 0 "phiopt1" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-4.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-4.c new file mode 100644 index 0000000000000000000000000000000000000000..0b6d667be868c2405eaefd17cb522da44bafa0e2 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-4.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-phiopt" } */ + +#include + +uint8_t three_max (uint8_t xc, uint8_t xm, uint8_t xy) { + uint8_t xk; + if (xc > xm) { + xk = (uint8_t) (xc > xy ? xc : xy); + } else { + xk = (uint8_t) (xm > xy ? xm : xy); + } + return xk; +} + +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 0 "phiopt1" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 3 "phiopt1" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-5.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-5.c new file mode 100644 index 0000000000000000000000000000000000000000..650601a3cc75d09a9e6e54a35f5b9993074f8510 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-5.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-phiopt" } */ + +#include + +uint8_t three_minmax1 (uint8_t xc, uint8_t xm, uint8_t xy) { + uint8_t xk; + if (xc > xm) { + xk = (uint8_t) (xc < xy ? xc : xy); + } else { + xk = (uint8_t) (xm < xy ? xm : xy); + } + return xk; +} + +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 2 "phiopt1" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 1 "phiopt1" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-6.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-6.c new file mode 100644 index 0000000000000000000000000000000000000000..a628f6d99222958cfd8c410f0e85639e3a49dd4b --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-6.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-phiopt" } */ + +#include + +uint8_t three_minmax3 (uint8_t xc, uint8_t xm, uint8_t xy) { + uint8_t xk; + if (xc > xm) { + xk = (uint8_t) (xy < xc ? xc : xy); + } else { + xk = (uint8_t) (xm < xy ? xm : xy); + } + return xk; +} + +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 1 "phiopt1" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 1 "phiopt1" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-7.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-7.c new file mode 100644 index 0000000000000000000000000000000000000000..cb42412c4ada433b2f59df0a8bef9fa7b1c5e104 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-7.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-phiopt" } */ + +#include + +uint8_t three_minmax2 (uint8_t xc, uint8_t xm, uint8_t xy) { + uint8_t xk; + if (xc > xm) { + xk = (uint8_t) (xc > xy ? xc : xy); + } else { + xk = (uint8_t) (xm < xy ? xm : xy); + } + return xk; +} +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 1 "phiopt1" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 1 "phiopt1" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-8.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-8.c new file mode 100644 index 0000000000000000000000000000000000000000..9cd050e932376bc50bd6ae60cb654fcab0bfdd1c --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-8.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-phiopt" } */ + +#include + +uint8_t three_minmax11 (uint8_t xc, uint8_t xm, uint8_t xy) { + uint8_t xk; + if (xc < xm) { + xk = (uint8_t) (xc > xy ? xc : xy); + } else { + xk = (uint8_t) (xm > xy ? xm : xy); + } + return xk; +} + +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 1 "phiopt1" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 2 "phiopt1" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-9.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-9.c new file mode 100644 index 0000000000000000000000000000000000000000..24f580271c3ac3945860b506d4dc7d178a826093 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-9.c @@ -0,0 +1,20 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-optimized" } */ + +#include + +uint8_t three_min (uint8_t xc, uint8_t xm, uint8_t xy) { + uint8_t xk; + xc=~xc; + xm=~xm; + xy=~xy; + if (xc < xm) { + xk = (uint8_t) (xc < xy ? xc : xy); + } else { + xk = (uint8_t) (xm < xy ? xm : xy); + } + return xk; +} + +/* { dg-final { scan-tree-dump-times "= ~" 1 "optimized" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 2 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/split-path-1.c b/gcc/testsuite/gcc.dg/tree-ssa/split-path-1.c index 8b23ef4c7a3484cdc1647ee6d1b150f15685beff..902dde44a50e171b4f34ba7247d75a32d2c860ed 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/split-path-1.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/split-path-1.c @@ -1,5 +1,5 @@ /* { dg-do run } */ -/* { dg-options "-O2 -fsplit-paths -fdump-tree-split-paths-details --param max-jump-thread-duplication-stmts=20" } */ +/* { dg-options "-O2 -fsplit-paths -fdump-tree-split-paths-details --param max-jump-thread-duplication-stmts=20 -fno-ssa-phiopt" } */ #include #include diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc index e61d9736937573d773acdf3e43a7c76074bfb2c7..df543b22cd720538c14bcea72fc78a8dec9bf12b 100644 --- a/gcc/tree-ssa-phiopt.cc +++ b/gcc/tree-ssa-phiopt.cc @@ -63,8 +63,8 @@ static gphi *factor_out_conditional_conversion (edge, edge, gphi *, tree, tree, gimple *); static int value_replacement (basic_block, basic_block, edge, edge, gphi *, tree, tree); -static bool minmax_replacement (basic_block, basic_block, - edge, edge, gphi *, tree, tree); +static bool minmax_replacement (basic_block, basic_block, basic_block, + edge, edge, gphi *, tree, tree, bool); static bool spaceship_replacement (basic_block, basic_block, edge, edge, gphi *, tree, tree); static bool cond_removal_in_builtin_zero_pattern (basic_block, basic_block, @@ -74,7 +74,7 @@ static bool cond_store_replacement (basic_block, basic_block, edge, edge, hash_set *); static bool cond_if_else_store_replacement (basic_block, basic_block, basic_block); static hash_set * get_non_trapping (); -static void replace_phi_edge_with_variable (basic_block, edge, gphi *, tree); +static void replace_phi_edge_with_variable (basic_block, edge, gphi *, tree, bool); static void hoist_adjacent_loads (basic_block, basic_block, basic_block, basic_block); static bool gate_hoist_loads (void); @@ -200,6 +200,7 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads, bool early_p) basic_block bb1, bb2; edge e1, e2; tree arg0, arg1; + bool diamond_p = false; bb = bb_order[i]; @@ -266,6 +267,9 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads, bool early_p) hoist_adjacent_loads (bb, bb1, bb2, bb3); continue; } + else if (EDGE_SUCC (bb1, 0)->dest == EDGE_SUCC (bb2, 0)->dest + && !empty_block_p (bb1)) + diamond_p = true; else continue; @@ -294,10 +298,13 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads, bool early_p) } else { - gimple_seq phis = phi_nodes (bb2); gimple_stmt_iterator gsi; bool candorest = true; + /* Check that we're looking for nested phis. */ + basic_block merge = diamond_p ? EDGE_SUCC (bb2, 0)->dest : bb2; + gimple_seq phis = phi_nodes (merge); + /* Value replacement can work with more than one PHI so try that first. */ if (!early_p) @@ -317,6 +324,7 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads, bool early_p) if (!candorest) continue; + e2 = diamond_p ? EDGE_SUCC (bb2, 0) : e2; phi = single_non_singleton_phi_for_edges (phis, e1, e2); if (!phi) continue; @@ -330,6 +338,7 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads, bool early_p) gphi *newphi; if (single_pred_p (bb1) + && !diamond_p && (newphi = factor_out_conditional_conversion (e1, e2, phi, arg0, arg1, cond_stmt))) @@ -344,20 +353,25 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads, bool early_p) } /* Do the replacement of conditional if it can be done. */ - if (!early_p && two_value_replacement (bb, bb1, e2, phi, arg0, arg1)) + if (!early_p + && !diamond_p + && two_value_replacement (bb, bb1, e2, phi, arg0, arg1)) cfgchanged = true; - else if (match_simplify_replacement (bb, bb1, e1, e2, phi, - arg0, arg1, - early_p)) + else if (!diamond_p + && match_simplify_replacement (bb, bb1, e1, e2, phi, + arg0, arg1, early_p)) cfgchanged = true; else if (!early_p + && !diamond_p && single_pred_p (bb1) && cond_removal_in_builtin_zero_pattern (bb, bb1, e1, e2, phi, arg0, arg1)) cfgchanged = true; - else if (minmax_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) + else if (minmax_replacement (bb, bb1, bb2, e1, e2, phi, arg0, arg1, + diamond_p)) cfgchanged = true; else if (single_pred_p (bb1) + && !diamond_p && spaceship_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) cfgchanged = true; } @@ -386,7 +400,7 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads, bool early_p) static void replace_phi_edge_with_variable (basic_block cond_block, - edge e, gphi *phi, tree new_tree) + edge e, gphi *phi, tree new_tree, bool delete_bb = true) { basic_block bb = gimple_bb (phi); gimple_stmt_iterator gsi; @@ -427,7 +441,7 @@ replace_phi_edge_with_variable (basic_block cond_block, edge_to_remove = EDGE_SUCC (cond_block, 1); else edge_to_remove = EDGE_SUCC (cond_block, 0); - if (EDGE_COUNT (edge_to_remove->dest->preds) == 1) + if (EDGE_COUNT (edge_to_remove->dest->preds) == 1 && delete_bb) { e->flags |= EDGE_FALLTHRU; e->flags &= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); @@ -1733,15 +1747,52 @@ value_replacement (basic_block cond_bb, basic_block middle_bb, return 0; } +/* If VAR is an SSA_NAME that points to a BIT_NOT_EXPR then return the TREE for + the value being inverted. */ + +static tree +strip_bit_not (tree var) +{ + if (TREE_CODE (var) != SSA_NAME) + return NULL_TREE; + + gimple *assign = SSA_NAME_DEF_STMT (var); + if (gimple_code (assign) != GIMPLE_ASSIGN) + return NULL_TREE; + + if (gimple_assign_rhs_code (assign) != BIT_NOT_EXPR) + return NULL_TREE; + + return gimple_assign_rhs1 (assign); +} + +/* Invert a MIN to a MAX or a MAX to a MIN expression CODE. */ + +enum tree_code +invert_minmax_code (enum tree_code code) +{ + switch (code) { + case MIN_EXPR: + return MAX_EXPR; + case MAX_EXPR: + return MIN_EXPR; + default: + gcc_unreachable (); + } +} + /* The function minmax_replacement does the main work of doing the minmax replacement. Return true if the replacement is done. Otherwise return false. BB is the basic block where the replacement is going to be done on. ARG0 - is argument 0 from the PHI. Likewise for ARG1. */ + is argument 0 from the PHI. Likewise for ARG1. + + If THREEWAY_P then expect the BB to be laid out in diamond shape with each + BB containing only a MIN or MAX expression. */ static bool -minmax_replacement (basic_block cond_bb, basic_block middle_bb, - edge e0, edge e1, gphi *phi, tree arg0, tree arg1) +minmax_replacement (basic_block cond_bb, basic_block middle_bb, basic_block alt_middle_bb, + edge e0, edge e1, gphi *phi, tree arg0, tree arg1, bool threeway_p) { tree result; edge true_edge, false_edge; @@ -1896,16 +1947,20 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb, if (false_edge->dest == middle_bb) false_edge = EDGE_SUCC (false_edge->dest, 0); + /* When THREEWAY_P then e1 will point to the edge of the final transition + from middle-bb to end. */ if (true_edge == e0) { - gcc_assert (false_edge == e1); + if (!threeway_p) + gcc_assert (false_edge == e1); arg_true = arg0; arg_false = arg1; } else { gcc_assert (false_edge == e0); - gcc_assert (true_edge == e1); + if (!threeway_p) + gcc_assert (true_edge == e1); arg_true = arg1; arg_false = arg0; } @@ -1937,6 +1992,165 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb, else return false; } + else if (middle_bb != alt_middle_bb && threeway_p) + { + /* Recognize the following case: + + if (smaller < larger) + a = MIN (smaller, c); + else + b = MIN (larger, c); + x = PHI + + This is equivalent to + + a = MIN (smaller, c); + x = MIN (larger, a); */ + + gimple *assign = last_and_only_stmt (middle_bb); + tree lhs, op0, op1, bound; + tree alt_lhs, alt_op0, alt_op1; + bool invert = false; + + if (!single_pred_p (middle_bb) + || !single_pred_p (alt_middle_bb) + || !single_succ_p (middle_bb) + || !single_succ_p (alt_middle_bb)) + return false; + + /* When THREEWAY_P then e1 will point to the edge of the final transition + from middle-bb to end. */ + if (true_edge == e0) + gcc_assert (false_edge == EDGE_PRED (e1->src, 0)); + else + gcc_assert (true_edge == EDGE_PRED (e1->src, 0)); + + bool valid_minmax_p = false; + gimple_stmt_iterator it1 + = gsi_start_nondebug_after_labels_bb (middle_bb); + gimple_stmt_iterator it2 + = gsi_start_nondebug_after_labels_bb (alt_middle_bb); + if (gsi_one_nondebug_before_end_p (it1) + && gsi_one_nondebug_before_end_p (it2)) + { + gimple *stmt1 = gsi_stmt (it1); + gimple *stmt2 = gsi_stmt (it2); + if (is_gimple_assign (stmt1) && is_gimple_assign (stmt2)) + { + enum tree_code code1 = gimple_assign_rhs_code (stmt1); + enum tree_code code2 = gimple_assign_rhs_code (stmt2); + valid_minmax_p = (code1 == MIN_EXPR || code1 == MAX_EXPR) + && (code2 == MIN_EXPR || code2 == MAX_EXPR); + } + } + + if (!valid_minmax_p) + return false; + + if (!assign + || gimple_code (assign) != GIMPLE_ASSIGN) + return false; + + lhs = gimple_assign_lhs (assign); + ass_code = gimple_assign_rhs_code (assign); + if (ass_code != MAX_EXPR && ass_code != MIN_EXPR) + return false; + + op0 = gimple_assign_rhs1 (assign); + op1 = gimple_assign_rhs2 (assign); + + assign = last_and_only_stmt (alt_middle_bb); + if (!assign + || gimple_code (assign) != GIMPLE_ASSIGN) + return false; + + alt_lhs = gimple_assign_lhs (assign); + if (ass_code != gimple_assign_rhs_code (assign)) + return false; + + if (!operand_equal_for_phi_arg_p (lhs, arg_true) + || !operand_equal_for_phi_arg_p (alt_lhs, arg_false)) + return false; + + alt_op0 = gimple_assign_rhs1 (assign); + alt_op1 = gimple_assign_rhs2 (assign); + + if ((operand_equal_for_phi_arg_p (op0, smaller) + || (alt_smaller + && operand_equal_for_phi_arg_p (op0, alt_smaller))) + && (operand_equal_for_phi_arg_p (alt_op0, larger) + || (alt_larger + && operand_equal_for_phi_arg_p (alt_op0, alt_larger)))) + { + /* We got here if the condition is true, i.e., SMALLER < LARGER. */ + if (!operand_equal_for_phi_arg_p (op1, alt_op1)) + return false; + + if ((arg0 = strip_bit_not (op0)) != NULL + && (arg1 = strip_bit_not (alt_op0)) != NULL + && (bound = strip_bit_not (op1)) != NULL) + { + minmax = MAX_EXPR; + ass_code = invert_minmax_code (ass_code); + invert = true; + } + else + { + bound = op1; + minmax = MIN_EXPR; + arg0 = op0; + arg1 = alt_op0; + } + } + else if ((operand_equal_for_phi_arg_p (op0, larger) + || (alt_larger + && operand_equal_for_phi_arg_p (op0, alt_larger))) + && (operand_equal_for_phi_arg_p (alt_op0, smaller) + || (alt_smaller + && operand_equal_for_phi_arg_p (alt_op0, alt_smaller)))) + { + /* We got here if the condition is true, i.e., SMALLER > LARGER. */ + if (!operand_equal_for_phi_arg_p (op1, alt_op1)) + return false; + + if ((arg0 = strip_bit_not (op0)) != NULL + && (arg1 = strip_bit_not (alt_op0)) != NULL + && (bound = strip_bit_not (op1)) != NULL) + { + minmax = MIN_EXPR; + ass_code = invert_minmax_code (ass_code); + invert = true; + } + else + { + bound = op1; + minmax = MAX_EXPR; + arg0 = op0; + arg1 = alt_op0; + } + } + else + return false; + + /* Emit the statement to compute min/max. */ + location_t locus = gimple_location (last_stmt (cond_bb)); + gimple_seq stmts = NULL; + tree phi_result = PHI_RESULT (phi); + result = gimple_build (&stmts, locus, minmax, TREE_TYPE (phi_result), + arg0, bound); + result = gimple_build (&stmts, locus, ass_code, TREE_TYPE (phi_result), + result, arg1); + if (invert) + result = gimple_build (&stmts, locus, BIT_NOT_EXPR, TREE_TYPE (phi_result), + result); + + gsi = gsi_last_bb (cond_bb); + gsi_insert_seq_before (&gsi, stmts, GSI_NEW_STMT); + + replace_phi_edge_with_variable (cond_bb, e1, phi, result, false); + + return true; + } else { /* Recognize the following case, assuming d <= u: