Hi! As discussed in the PR, ideally this should be done in the middle-end, but no fix materialized for it during the last 18 months and is unlikely to happen for GCC 5 either, so this patch just restores what the FEs used to produce. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2014-12-03 Jakub Jelinek <ja...@redhat.com> PR c++/56493 * convert.c (convert_to_real, convert_to_expr, convert_to_complex): Handle COMPOUND_EXPR. * c-c++-common/pr56493.c: New test. --- gcc/convert.c.jj 2014-11-11 00:06:25.016769050 +0100 +++ gcc/convert.c 2014-12-03 11:22:16.193539558 +0100 @@ -99,6 +99,15 @@ convert_to_real (tree type, tree expr) enum built_in_function fcode = builtin_mathfn_code (expr); tree itype = TREE_TYPE (expr); + if (TREE_CODE (expr) == COMPOUND_EXPR) + { + tree t = convert_to_real (type, TREE_OPERAND (expr, 1)); + if (t == TREE_OPERAND (expr, 1)) + return expr; + return build2_loc (EXPR_LOCATION (expr), COMPOUND_EXPR, TREE_TYPE (t), + TREE_OPERAND (expr, 0), t); + } + /* Disable until we figure out how to decide whether the functions are present in runtime. */ /* Convert (float)sqrt((double)x) where x is float into sqrtf(x) */ @@ -406,6 +415,15 @@ convert_to_integer (tree type, tree expr return error_mark_node; } + if (ex_form == COMPOUND_EXPR) + { + tree t = convert_to_integer (type, TREE_OPERAND (expr, 1)); + if (t == TREE_OPERAND (expr, 1)) + return expr; + return build2_loc (EXPR_LOCATION (expr), COMPOUND_EXPR, TREE_TYPE (t), + TREE_OPERAND (expr, 0), t); + } + /* Convert e.g. (long)round(d) -> lround(d). */ /* If we're converting to char, we may encounter differing behavior between converting from double->char vs double->long->char. @@ -926,6 +944,14 @@ convert_to_complex (tree type, tree expr if (TYPE_MAIN_VARIANT (elt_type) == TYPE_MAIN_VARIANT (subtype)) return expr; + else if (TREE_CODE (expr) == COMPOUND_EXPR) + { + tree t = convert_to_complex (type, TREE_OPERAND (expr, 1)); + if (t == TREE_OPERAND (expr, 1)) + return expr; + return build2_loc (EXPR_LOCATION (expr), COMPOUND_EXPR, + TREE_TYPE (t), TREE_OPERAND (expr, 0), t); + } else if (TREE_CODE (expr) == COMPLEX_EXPR) return fold_build2 (COMPLEX_EXPR, type, convert (subtype, TREE_OPERAND (expr, 0)), --- gcc/testsuite/c-c++-common/pr56493.c.jj 2014-12-03 11:22:16.193539558 +0100 +++ gcc/testsuite/c-c++-common/pr56493.c 2014-12-03 11:22:16.193539558 +0100 @@ -0,0 +1,16 @@ +/* PR c++/56493 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-gimple" } */ + +unsigned long long bar (void); +int x; + +void +foo (void) +{ + x += bar (); +} + +/* Verify we narrow the addition from unsigned long long to unsigned int type. */ +/* { dg-final { scan-tree-dump " (\[a-zA-Z._0-9]*) = \\(unsigned int\\) \[^;\n\r]*;.* (\[a-zA-Z._0-9]*) = \\(unsigned int\\) \[^;\n\r]*;.* = \\1 \\+ \\2;" "gimple" { target { ilp32 || lp64 } } } } */ +/* { dg-final { cleanup-tree-dump "gimple" } } */ Jakub