diff options
| -rw-r--r-- | gcc/df-scan.c | 18 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr101170.c | 37 |
2 files changed, 52 insertions, 3 deletions
diff --git a/gcc/df-scan.c b/gcc/df-scan.c index e9da64f..3dbda7a 100644 --- a/gcc/df-scan.c +++ b/gcc/df-scan.c @@ -2576,9 +2576,21 @@ df_ref_record (enum df_ref_class cl, if (GET_CODE (reg) == SUBREG) { - regno += subreg_regno_offset (regno, GET_MODE (SUBREG_REG (reg)), - SUBREG_BYTE (reg), GET_MODE (reg)); - endregno = regno + subreg_nregs (reg); + int off = subreg_regno_offset (regno, GET_MODE (SUBREG_REG (reg)), + SUBREG_BYTE (reg), GET_MODE (reg)); + unsigned int nregno = regno + off; + endregno = nregno + subreg_nregs (reg); + if (off < 0 && regno < (unsigned) -off) + /* Deal with paradoxical SUBREGs on big endian where + in debug insns the hard reg number might be smaller + than -off, such as (subreg:DI (reg:SI 0 [+4 ]) 0)); + RA decisions shouldn't be affected by debug insns + and so RA can decide to put pseudo into a hard reg + with small REGNO, even when it is referenced in + a paradoxical SUBREG in a debug insn. */ + regno = 0; + else + regno = nregno; } else endregno = END_REGNO (reg); diff --git a/gcc/testsuite/gcc.dg/pr101170.c b/gcc/testsuite/gcc.dg/pr101170.c new file mode 100644 index 0000000..fc81062 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr101170.c @@ -0,0 +1,37 @@ +/* PR middle-end/101170 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -g" } */ + +#include <stdarg.h> + +struct S { int a; int b[4]; } s; +va_list ap; +int i; +long long l; + +struct S +foo (int x) +{ + struct S a = {}; + do + if (x) + return a; + while (1); +} + +__attribute__((noipa)) void +bar (void) +{ + for (; i; i++) + l |= va_arg (ap, long long) << s.b[i]; + if (l) + foo (l); +} + +void +baz (int v, ...) +{ + va_start (ap, v); + bar (); + va_end (ap); +} |