From 9300be2c74e35709ded209a378edab91a9073fbc Mon Sep 17 00:00:00 2001 From: Martin Jambor Date: Tue, 21 Apr 2020 14:20:37 +0200 Subject: [PATCH] sra-9: Fix sra_modify_expr handling of partial writes (PR 94482) This is a fairly straightforward backport of the mainline fix for PR 94482. When sra_modify_expr is invoked on an expression that modifies only part of the underlying replacement, such as a BIT_FIELD_REF on a LHS of an assignment and the SRA replacement's type is not compatible with what is being replaced (0th operand of the B_F_R in the above example), it does not work properly, basically throwing away the part of the expr that should have stayed intact. This is fixed in two ways. For BIT_FIELD_REFs, which operate on the binary image of the replacement (and so in a way serve as a VIEW_CONVERT_EXPR) we just do not bother with converting. For REALPART_EXPRs and IMAGPART_EXPRs, if the replacement is not a register, we insert a VIEW_CONVERT_EXPR under the complex partial access expression, which is always OK, for loads from registers we take the extra step of converting it to a temporary. This revealed a bug in fwprop which is fixed with the hunk from Richi. This is the only difference from the mainline patch which has two hunks, but the code handling BIT_FIELD_REF is not present in gcc-9. Oh, and the testcase options were changed to what Jakub put there on the mainline to suppress all vector ABI warnings. Bootstrapped and tested on x86_64-linux. 2020-04-21 Martin Jambor Backport from master 2020-04-09 Martin Jambor Richard Biener PR tree-optimization/94482 * tree-sra.c (create_access_replacement): Dump new replacement with TDF_UID. (sra_modify_expr): Fix handling of cases when the original EXPR writes to only part of the replacement. * tree-ssa-forwprop.c (pass_forwprop::execute): Properly verify the first operand of combinations into REAL/IMAGPART_EXPR and BIT_FIELD_REF. testsuite/ * gcc.dg/torture/pr94482.c: New test. * gcc.dg/tree-ssa/pr94482-2.c: Likewise. --- gcc/ChangeLog | 15 +++++++ gcc/testsuite/ChangeLog | 9 ++++ gcc/testsuite/gcc.dg/torture/pr94482.c | 36 ++++++++++++++++ gcc/testsuite/gcc.dg/tree-ssa/pr94482-2.c | 50 +++++++++++++++++++++++ gcc/tree-sra.c | 31 ++++++++++++-- gcc/tree-ssa-forwprop.c | 3 +- 6 files changed, 139 insertions(+), 5 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/torture/pr94482.c create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr94482-2.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 93bd849accac..4cb1497a61f2 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,18 @@ +2020-04-21 Martin Jambor + + Backport from master + 2020-04-09 Martin Jambor + Richard Biener + + PR tree-optimization/94482 + * tree-sra.c (create_access_replacement): Dump new replacement with + TDF_UID. + (sra_modify_expr): Fix handling of cases when the original EXPR writes + to only part of the replacement. + * tree-ssa-forwprop.c (pass_forwprop::execute): Properly verify + the first operand of combinations into REAL/IMAGPART_EXPR and + BIT_FIELD_REF. + 2020-04-20 H.J. Lu Backport from master diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index fb039ee0e97a..74a3cdf7b80d 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,12 @@ +2020-04-21 Martin Jambor + + Backport from master + 2020-04-09 Martin Jambor + + PR tree-optimization/94482 + * gcc.dg/torture/pr94482.c: New test. + * gcc.dg/tree-ssa/pr94482-2.c: Likewise. + 2020-04-20 Harald Anlauf Backport from mainline. diff --git a/gcc/testsuite/gcc.dg/torture/pr94482.c b/gcc/testsuite/gcc.dg/torture/pr94482.c new file mode 100644 index 000000000000..9264842e3494 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr94482.c @@ -0,0 +1,36 @@ +/* { dg-do run } */ +/* { dg-additional-options "-Wno-psabi -w" } */ +/* { dg-additional-options "-msse2" { target sse2_runtime } } */ + +typedef unsigned V __attribute__ ((__vector_size__ (16))); +union U +{ + V j; + unsigned long long i __attribute__ ((__vector_size__ (16))); +}; + +static inline __attribute__((always_inline)) V +foo (unsigned long long a) +{ + union U z = { .j = (V) {} }; + for (unsigned long i = 0; i < 1; i++) + z.i[i] = a; + return z.j; +} + +static inline __attribute__((always_inline)) V +bar (V a, unsigned long long i, int q) +{ + union U z = { .j = a }; + z.i[q] = i; + return z.j; +} + +int +main () +{ + union U z = { .j = bar (foo (1729), 2, 1) }; + if (z.i[0] != 1729) + __builtin_abort (); + return 0; +} diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr94482-2.c b/gcc/testsuite/gcc.dg/tree-ssa/pr94482-2.c new file mode 100644 index 000000000000..fcac9d5e4398 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr94482-2.c @@ -0,0 +1,50 @@ +/* { dg-do run } */ +/* { dg-options "-O1" } */ + +typedef unsigned long V __attribute__ ((__vector_size__ (8))); +typedef _Complex int Ci; +typedef _Complex float Cf; + +union U +{ + Ci ci; + Cf cf; +}; + +volatile Ci vgi; + +Cf foo (Cf c) +{ + __real c = 0x1ffp10; + return c; +} + +Ci ioo (Ci c) +{ + __real c = 50; + return c; +} + + +int main (int argc, char *argv[]) +{ + union U u; + + __real u.ci = 500; + __imag u.ci = 1000; + vgi = u.ci; + + u.ci = ioo (u.ci); + __imag u.ci = 100; + + if (__real u.ci != 50 || __imag u.ci != 100) + __builtin_abort(); + + u.cf = foo (u.cf); + __imag u.cf = 0x1p3; + + if (__real u.cf != 0x1ffp10 || __imag u.cf != 0x1p3) + __builtin_abort(); + + return 0; +} diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c index 0a5c24a183a7..805839cac503 100644 --- a/gcc/tree-sra.c +++ b/gcc/tree-sra.c @@ -2329,7 +2329,7 @@ create_access_replacement (struct access *access, tree reg_type = NULL_TREE) print_generic_expr (dump_file, access->base); fprintf (dump_file, " offset: %u, size: %u: ", (unsigned) access->offset, (unsigned) access->size); - print_generic_expr (dump_file, repl); + print_generic_expr (dump_file, repl, TDF_UID); fprintf (dump_file, "\n"); } } @@ -3187,6 +3187,7 @@ sra_modify_expr (tree *expr, gimple_stmt_iterator *gsi, bool write) location_t loc; struct access *access; tree type, bfr, orig_expr; + bool partial_cplx_access = false; if (TREE_CODE (*expr) == BIT_FIELD_REF) { @@ -3197,7 +3198,10 @@ sra_modify_expr (tree *expr, gimple_stmt_iterator *gsi, bool write) bfr = NULL_TREE; if (TREE_CODE (*expr) == REALPART_EXPR || TREE_CODE (*expr) == IMAGPART_EXPR) - expr = &TREE_OPERAND (*expr, 0); + { + expr = &TREE_OPERAND (*expr, 0); + partial_cplx_access = true; + } access = get_access_for_expr (*expr); if (!access) return false; @@ -3225,13 +3229,32 @@ sra_modify_expr (tree *expr, gimple_stmt_iterator *gsi, bool write) be accessed as a different type too, potentially creating a need for type conversion (see PR42196) and when scalarized unions are involved in assembler statements (see PR42398). */ - if (!useless_type_conversion_p (type, access->type)) + if (!bfr && !useless_type_conversion_p (type, access->type)) { tree ref; ref = build_ref_for_model (loc, orig_expr, 0, access, gsi, false); - if (write) + if (partial_cplx_access) + { + /* VIEW_CONVERT_EXPRs in partial complex access are always fine in + the case of a write because in such case the replacement cannot + be a gimple register. In the case of a load, we have to + differentiate in between a register an non-register + replacement. */ + tree t = build1 (VIEW_CONVERT_EXPR, type, repl); + gcc_checking_assert (!write || access->grp_partial_lhs); + if (!access->grp_partial_lhs) + { + tree tmp = make_ssa_name (type); + gassign *stmt = gimple_build_assign (tmp, t); + /* This is always a read. */ + gsi_insert_before (gsi, stmt, GSI_SAME_STMT); + t = tmp; + } + *expr = t; + } + else if (write) { gassign *stmt; diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c index bbfa1bc6fae1..ca5443b79b3d 100644 --- a/gcc/tree-ssa-forwprop.c +++ b/gcc/tree-ssa-forwprop.c @@ -2357,7 +2357,8 @@ pass_forwprop::execute (function *fun) continue; if (!is_gimple_assign (use_stmt) || (gimple_assign_rhs_code (use_stmt) != REALPART_EXPR - && gimple_assign_rhs_code (use_stmt) != IMAGPART_EXPR)) + && gimple_assign_rhs_code (use_stmt) != IMAGPART_EXPR) + || TREE_OPERAND (gimple_assign_rhs1 (use_stmt), 0) != lhs) { rewrite = false; break; -- 2.47.3