On Fri, Jan 20, 2012 at 10:06 AM, Jiangning Liu <jiangning....@arm.com> wrote: >> It's definitely not ok at this stage but at most for next stage1. > > OK. I may wait until next stage1. > >> This is a very narrow pattern-match. It doesn't allow for &a[i].x for >> example, >> even if a[i] is a one-element structure. I think the canonical way of >> handling >> ADDR_EXPR is to use sth like >> >> base = get_inner_reference (TREE_OPERAND (rhs1, 0), ..., &offset, ...); >> base = build1 (ADDR_EXPR, TREE_TYPE (rhs1), base); >> chrec1 = analyze_scalar_evolution (loop, base); >> chrec2 = analyze_scalar_evolution (loop, offset); >> chrec1 = chrec_convert (type, chrec1, at_stmt); >> chrec2 = chrec_convert (TREE_TYPE (offset), chrec2, at_stmt); >> res = chrec_fold_plus (type, chrec1, chrec2); >> >> where you probably need to handle scev_not_known when analyzing offset >> (which might be NULL). You also need to add bitpos to the base address >> (in bytes, of course). Note that the &MEM_REF case would naturally >> work >> with this as well. > > OK. New patch is like below, and bootstrapped on x86-32.
You want instead of + if (TREE_CODE (TREE_OPERAND (rhs1, 0)) == ARRAY_REF + || TREE_CODE (TREE_OPERAND (rhs1, 0)) == MEM_REF + || TREE_CODE (TREE_OPERAND (rhs1, 0)) == COMPONENT_REF) + { if (TREE_CODE (TREE_OPERAND (rhs1, 0)) == MEM_REF || handled_component_p (TREE_OPERAND (rhs1, 0))) { + base = build1 (ADDR_EXPR, TREE_TYPE (rhs1), base); + chrec1 = analyze_scalar_evolution (loop, base); can you please add a wrapper tree analyze_scalar_evolution_for_address_of (struct loop *loop, tree var) { return analyze_scalar_evolution (loop, build_fold_addr_expr (var)); } and call that instead of building the ADDR_EXPR there? We want to avoid building that tree node, but even such a simple wrapper would be prefered. + if (bitpos) if (bitpos != 0) + chrec3 = build_int_cst (integer_type_node, + bitpos / BITS_PER_UNIT); please use size_int (bitpos / BITS_PER_UNIT) instead. Using integer_type_node is definitely wrong. Ok with that changes. Thanks, Richard. > ChangeLog: > > 2012-01-20 Jiangning Liu <jiangning....@arm.com> > > * tree-scalar-evolution (interpret_rhs_expr): generate chrec for > array reference and component reference. > > > ChangeLog for testsuite: > > 2012-01-20 Jiangning Liu <jiangning....@arm.com> > > * gcc.dg/tree-ssa/scev-3.c: New. > * gcc.dg/tree-ssa/scev-4.c: New. > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/scev-3.c > b/gcc/testsuite/gcc.dg/tree-ssa/scev-3.c > new file mode 100644 > index 0000000..28d5c93 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/tree-ssa/scev-3.c > @@ -0,0 +1,18 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -fdump-tree-optimized" } */ > + > +int *a_p; > +int a[1000]; > + > +f(int k) > +{ > + int i; > + > + for (i=k; i<1000; i+=k) { > + a_p = &a[i]; > + *a_p = 100; > + } > +} > + > +/* { dg-final { scan-tree-dump-times "&a" 1 "optimized" } } */ > +/* { dg-final { cleanup-tree-dump "optimized" } } */ > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/scev-4.c > b/gcc/testsuite/gcc.dg/tree-ssa/scev-4.c > new file mode 100644 > index 0000000..6c1e530 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/tree-ssa/scev-4.c > @@ -0,0 +1,23 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -fdump-tree-optimized" } */ > + > +typedef struct { > + int x; > + int y; > +} S; > + > +int *a_p; > +S a[1000]; > + > +f(int k) > +{ > + int i; > + > + for (i=k; i<1000; i+=k) { > + a_p = &a[i].y; > + *a_p = 100; > + } > +} > + > +/* { dg-final { scan-tree-dump-times "&a" 1 "optimized" } } */ > +/* { dg-final { cleanup-tree-dump "optimized" } } */ > diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c > index 2077c8d..4e06b75 > --- a/gcc/tree-scalar-evolution.c > +++ b/gcc/tree-scalar-evolution.c > @@ -1712,16 +1712,61 @@ interpret_rhs_expr (struct loop *loop, gimple > at_stmt, > switch (code) > { > case ADDR_EXPR: > - /* Handle &MEM[ptr + CST] which is equivalent to POINTER_PLUS_EXPR. > */ > - if (TREE_CODE (TREE_OPERAND (rhs1, 0)) != MEM_REF) > - { > - res = chrec_dont_know; > - break; > - } > + if (TREE_CODE (TREE_OPERAND (rhs1, 0)) == ARRAY_REF > + || TREE_CODE (TREE_OPERAND (rhs1, 0)) == MEM_REF > + || TREE_CODE (TREE_OPERAND (rhs1, 0)) == COMPONENT_REF) > + { > + enum machine_mode mode; > + HOST_WIDE_INT bitsize, bitpos; > + int unsignedp; > + int volatilep = 0; > + tree base, offset; > + tree chrec3; > + > + base = get_inner_reference (TREE_OPERAND (rhs1, 0), > + &bitsize, &bitpos, &offset, > + &mode, &unsignedp, &volatilep, false); > + > + if (TREE_CODE (base) == MEM_REF) > + { > + rhs2 = TREE_OPERAND (base, 1); > + rhs1 = TREE_OPERAND (base, 0); > + > + chrec1 = analyze_scalar_evolution (loop, rhs1); > + chrec2 = analyze_scalar_evolution (loop, rhs2); > + chrec1 = chrec_convert (type, chrec1, at_stmt); > + chrec2 = chrec_convert (TREE_TYPE (rhs2), chrec2, at_stmt); > + res = chrec_fold_plus (type, chrec1, chrec2); > + } > + else > + { > + base = build1 (ADDR_EXPR, TREE_TYPE (rhs1), base); > + chrec1 = analyze_scalar_evolution (loop, base); > + chrec1 = chrec_convert (type, chrec1, at_stmt); > + res = chrec1; > + } > > - rhs2 = TREE_OPERAND (TREE_OPERAND (rhs1, 0), 1); > - rhs1 = TREE_OPERAND (TREE_OPERAND (rhs1, 0), 0); > - /* Fall through. */ > + if (offset != NULL_TREE) > + { > + chrec2 = analyze_scalar_evolution (loop, offset); > + chrec2 = chrec_convert (TREE_TYPE (offset), chrec2, at_stmt); > + res = chrec_fold_plus (type, res, chrec2); > + } > + > + if (bitpos) > + { > + gcc_assert ((bitpos % BITS_PER_UNIT) == 0); > + > + chrec3 = build_int_cst (integer_type_node, > + bitpos / BITS_PER_UNIT); > + chrec3 = analyze_scalar_evolution (loop, chrec3); > + chrec3 = chrec_convert (integer_type_node, chrec3, at_stmt); > + res = chrec_fold_plus (type, res, chrec3); > + } > + } > + else > + res = chrec_dont_know; > + break; > > case POINTER_PLUS_EXPR: > chrec1 = analyze_scalar_evolution (loop, rhs1); > > Thanks, > -Jiangning >