The following reverts back to the old unroll heuristics before my
PR91975 changes but implements "consistency" the other way around.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2019-11-15 Richard Biener <rguent...@suse.de>
PR tree-optimization/92039
PR tree-optimization/91975
* tree-ssa-loop-ivcanon.c (constant_after_peeling): Revert
previous change, treat invariants consistently as non-constant.
(tree_estimate_loop_size): Ternary ops with just the first op
constant are not optimized away.
* gcc.dg/tree-ssa/cunroll-2.c: Revert to state previous to
unroller adjustment.
* g++.dg/tree-ssa/ivopts-3.C: Likewise.
Index: gcc/tree-ssa-loop-ivcanon.c
===================================================================
--- gcc/tree-ssa-loop-ivcanon.c (revision 278276)
+++ gcc/tree-ssa-loop-ivcanon.c (working copy)
@@ -163,7 +163,7 @@ struct loop_size
static bool
constant_after_peeling (tree op, gimple *stmt, class loop *loop)
{
- if (is_gimple_min_invariant (op))
+ if (CONSTANT_CLASS_P (op))
return true;
/* We can still fold accesses to constant arrays when index is known. */
@@ -195,8 +195,9 @@ constant_after_peeling (tree op, gimple
/* Induction variables are constants when defined in loop. */
if (loop_containing_stmt (stmt) != loop)
return false;
- tree ev = instantiate_parameters (loop, analyze_scalar_evolution (loop, op));
- if (chrec_contains_undetermined (ev))
+ tree ev = analyze_scalar_evolution (loop, op);
+ if (chrec_contains_undetermined (ev)
+ || chrec_contains_symbols (ev))
return false;
return true;
}
@@ -293,7 +294,8 @@ tree_estimate_loop_size (class loop *loo
stmt, loop)
&& (gimple_assign_rhs_class (stmt) != GIMPLE_BINARY_RHS
|| constant_after_peeling (gimple_assign_rhs2 (stmt),
- stmt, loop)))
+ stmt, loop))
+ && gimple_assign_rhs_class (stmt) != GIMPLE_TERNARY_RHS)
{
size->constant_iv = true;
if (dump_file && (dump_flags & TDF_DETAILS))
Index: gcc/testsuite/gcc.dg/tree-ssa/cunroll-2.c
===================================================================
--- gcc/testsuite/gcc.dg/tree-ssa/cunroll-2.c (revision 278276)
+++ gcc/testsuite/gcc.dg/tree-ssa/cunroll-2.c (working copy)
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O3 -fdump-tree-cunrolli-details" } */
+/* { dg-options "-O3 -fdump-tree-cunroll-details" } */
int a[2];
int test2 (void);
void
@@ -14,4 +14,4 @@ test(int c)
}
}
/* We are not able to get rid of the final conditional because the loop has
two exits. */
-/* { dg-final { scan-tree-dump "loop with 2 iterations completely unrolled"
"cunrolli"} } */
+/* { dg-final { scan-tree-dump "loop with 1 iterations completely unrolled"
"cunroll"} } */
Index: gcc/testsuite/g++.dg/tree-ssa/ivopts-3.C
===================================================================
--- gcc/testsuite/g++.dg/tree-ssa/ivopts-3.C (revision 278276)
+++ gcc/testsuite/g++.dg/tree-ssa/ivopts-3.C (working copy)
@@ -70,8 +70,6 @@ int main ( int , char** ) {
return 0;
}
-// Verify that on x86_64 and i?86 we unroll the innsermost loop and
-// use three IVs for the then innermost loop
+// Verify that on x86_64 and i?86 we use a single IV for the innermost loop
-// { dg-final { scan-tree-dump "Selected IV set for loop \[0-9\]* at \[^
\]*:63, 127 avg niters, 3 IVs" "ivopts" { target x86_64-*-* i?86-*-* } } }
-// { dg-final { scan-tree-dump-not "Selected IV set for loop \[0-9\]* at \[^
\]*:64" "ivopts" { target x86_64-*-* i?86-*-* } } }
+// { dg-final { scan-tree-dump "Selected IV set for loop \[0-9\]* at \[^
\]*:64, 3 avg niters, 1 IVs" "ivopts" { target x86_64-*-* i?86-*-* } } }
