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[gomp] Fix !$omp atomic (PR fortran/34020)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Richard Henderson <rth at redhat dot com>, Diego Novillo <dnovillo at google dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Fri, 9 Nov 2007 03:39:35 -0500
- Subject: [gomp] Fix !$omp atomic (PR fortran/34020)
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
On the following testcase lhsaddr is
(real4 *) lhs
where lhs has real4 & type. But unshare_body unshares the NOP_EXPR,
so in goa_lhs_expr_p the NOP_EXPR addresses aren't equal anymore, which
means that the read from *lhs is done before the loop and so is the floating
point addition, which means the operation is no longer atomic.
Fixed by going through any nops. Tested on x86_64-linux.
Ok for trunk/4.2/4.1?
2007-11-09 Jakub Jelinek <jakub@redhat.com>
PR fortran/34020
* gimplify.c (goa_lhs_expr_p): Inside INDIRECT_REF handle unshared
nops.
* testsuite/libgomp.fortran/pr34020.f90: New test.
--- gcc/gimplify.c.jj 2007-11-08 22:50:35.000000000 +0100
+++ gcc/gimplify.c 2007-11-09 08:48:25.000000000 +0100
@@ -5291,8 +5291,22 @@ goa_lhs_expr_p (tree expr, tree addr)
== TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (expr, 0)))))
expr = TREE_OPERAND (expr, 0);
- if (TREE_CODE (expr) == INDIRECT_REF && TREE_OPERAND (expr, 0) == addr)
- return true;
+ if (TREE_CODE (expr) == INDIRECT_REF)
+ {
+ expr = TREE_OPERAND (expr, 0);
+ while (expr != addr
+ && (TREE_CODE (expr) == NOP_EXPR
+ || TREE_CODE (expr) == CONVERT_EXPR
+ || TREE_CODE (expr) == NON_LVALUE_EXPR)
+ && TREE_CODE (expr) == TREE_CODE (addr)
+ && TYPE_MAIN_VARIANT (TREE_TYPE (expr))
+ == TYPE_MAIN_VARIANT (TREE_TYPE (addr)))
+ {
+ expr = TREE_OPERAND (expr, 0);
+ addr = TREE_OPERAND (addr, 0);
+ }
+ return expr == addr;
+ }
if (TREE_CODE (addr) == ADDR_EXPR && expr == TREE_OPERAND (addr, 0))
return true;
return false;
--- libgomp/testsuite/libgomp.fortran/pr34020.f90.jj 2007-11-09 08:56:44.000000000 +0100
+++ libgomp/testsuite/libgomp.fortran/pr34020.f90 2007-11-09 08:56:29.000000000 +0100
@@ -0,0 +1,19 @@
+! PR fortran/34020
+! { dg-do run }
+
+ subroutine atomic_add(lhs, rhs)
+ real lhs, rhs
+!$omp atomic
+ lhs = rhs + lhs
+ end
+
+ real lhs, rhs
+ integer i
+ lhs = 0
+ rhs = 1
+!$omp parallel do num_threads(8) shared(lhs, rhs)
+ do i = 1, 300000
+ call atomic_add(lhs, rhs)
+ enddo
+ if (lhs .ne. 300000) call abort
+ end
Jakub