The following patch fixes http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56225
The patch was successfully bootstrapped and tested on x86/x86-64. Committed as rev. 195856. 2013-02-07 Vladimir Makarov <vmaka...@redhat.com> PR rtl-optimization/56225 * lra-constraints.c (process_alt_operands): Check that reload hard reg can hold value for strict_low_part. 2013-02-07 Vladimir Makarov <vmaka...@redhat.com> PR rtl-optimization/56225 * gcc.target/i386/pr56225.c: New test.
Index: lra-constraints.c =================================================================== --- lra-constraints.c (revision 195807) +++ lra-constraints.c (working copy) @@ -1895,7 +1895,22 @@ process_alt_operands (int only_alternati ? in_hard_reg_set_p (this_alternative_set, mode, hard_regno[nop]) : in_class_p (op, this_alternative, NULL)))) - losers++; + { + /* Strict_low_part requires reload the register not + the sub-register. In this case we should check + that a final reload hard reg can hold the + value. */ + if (curr_static_id->operand[nop].strict_low + && REG_P (op) + && hard_regno[nop] < 0 + && GET_CODE (*curr_id->operand_loc[nop]) == SUBREG + && ira_class_hard_regs_num[this_alternative] > 0 + && ! HARD_REGNO_MODE_OK (ira_class_hard_regs + [this_alternative][0], + GET_MODE (op))) + goto fail; + losers++; + } if (operand_reg[nop] != NULL_RTX /* Output operands and matched input operands are not inherited. The following conditions do not Index: testsuite/gcc.target/i386/pr56225.c =================================================================== --- testsuite/gcc.target/i386/pr56225.c (revision 0) +++ testsuite/gcc.target/i386/pr56225.c (working copy) @@ -0,0 +1,12 @@ +/* PR target/56225 */ +/* { dg-do compile { target { ia32 } } } */ +/* { dg-options "-O2 -march=pentium3 -mtune=generic" } */ + +void bar (int); + +void +foo (int x, int y) +{ + __attribute__ ((vector_size (8 * sizeof (short)))) short s0 = { x }; + bar ((short) (long) &s0 + y); +}