struct C { unsigned int c; struct D { unsigned int columns : 4; unsigned int fore : 9; unsigned int back : 9; unsigned int fragment : 1; unsigned int standout : 1; unsigned int underline : 1; unsigned int strikethrough : 1; unsigned int reverse : 1; unsigned int blink : 1; unsigned int half : 1; unsigned int bold : 1; unsigned int invisible : 1; unsigned int pad : 1; } attr; };
struct A { struct C *data; unsigned int len; }; struct B { struct A *cells; unsigned char soft_wrapped : 1; }; struct E { long row, col; struct C defaults; }; __attribute__ ((noinline)) void foo (struct E *screen, unsigned int c, int columns, struct B *row) { struct D attr; long col; int i; col = screen->col; attr = screen->defaults.attr; attr.columns = columns; row->cells->data[col].c = c; row->cells->data[col].attr = attr; col++; attr.fragment = 1; for (i = 1; i < columns; i++) { row->cells->data[col].c = c; row->cells->data[col].attr = attr; col++; } } int main (void) { struct E e = {.row = 5,.col = 0,.defaults = {6, {-1, -1, -1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0}} }; struct C c[4]; struct A a = { c, 4 }; struct B b = { &a, 1 }; struct D d; __builtin_memset (&c, 0, sizeof c); foo (&e, 65, 2, &b); d = e.defaults.attr; d.columns = 2; if (__builtin_memcmp (&d, &c[0].attr, sizeof d)) __builtin_abort (); d.fragment = 1; if (__builtin_memcmp (&d, &c[1].attr, sizeof d)) __builtin_abort (); return 0; } is miscompiled at -O1 and above, works with -fno-tree-sra. -- Summary: [4.4 Regression] SRA miscompilation of vte Product: gcc Version: 4.4.0 Status: UNCONFIRMED Keywords: wrong-code Severity: normal Priority: P3 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: jakub at gcc dot gnu dot org GCC target triplet: x86_64-linux http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39339