Hi!
The following testcase FAILs, because replace_rtx replaces a REG with
CONST_WIDE_INT inside of a SUBREG, which is an invalid transformation
because a SUBREG relies on SUBREG_REG having non-VOIDmode but
CONST_WIDE_INT has VOIDmode.
replace_rtx already has code to deal with it, but it was doing
it only for CONST_INTs. The following patch does it also for
VOIDmode CONST_DOUBLE or CONST_WIDE_INT.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2022-04-22 Jakub Jelinek <ja...@redhat.com>
PR rtl-optimization/105333
* rtlanal.cc (replace_rtx): Use simplify_subreg or
simplify_unary_operation if CONST_SCALAR_INT_P rather than just
CONST_INT_P.
* gcc.dg/pr105333.c: New test.
--- gcc/rtlanal.cc.jj 2022-02-08 20:08:03.912540713 +0100
+++ gcc/rtlanal.cc 2022-04-21 15:45:23.219769629 +0200
@@ -3390,7 +3390,7 @@ replace_rtx (rtx x, rtx from, rtx to, bo
{
rtx new_rtx = replace_rtx (SUBREG_REG (x), from, to, all_regs);
- if (CONST_INT_P (new_rtx))
+ if (CONST_SCALAR_INT_P (new_rtx))
{
x = simplify_subreg (GET_MODE (x), new_rtx,
GET_MODE (SUBREG_REG (x)),
@@ -3406,7 +3406,7 @@ replace_rtx (rtx x, rtx from, rtx to, bo
{
rtx new_rtx = replace_rtx (XEXP (x, 0), from, to, all_regs);
- if (CONST_INT_P (new_rtx))
+ if (CONST_SCALAR_INT_P (new_rtx))
{
x = simplify_unary_operation (ZERO_EXTEND, GET_MODE (x),
new_rtx, GET_MODE (XEXP (x, 0)));
--- gcc/testsuite/gcc.dg/pr105333.c.jj 2022-04-21 15:48:08.310468926 +0200
+++ gcc/testsuite/gcc.dg/pr105333.c 2022-04-21 15:47:49.578729973 +0200
@@ -0,0 +1,21 @@
+/* PR rtl-optimization/105333 */
+/* { dg-do compile { target int128 } } */
+/* { dg-options "-Og -fno-tree-coalesce-vars -fno-tree-fre" } */
+
+int g;
+short s;
+
+static inline unsigned short
+bar (short a, __int128 b)
+{
+ b ^= (unsigned long) -a;
+ __builtin_strncpy ((void *) &s, (void *) &a, 1);
+ b *= 14;
+ return b;
+}
+
+void
+foo (void)
+{
+ g *= (__int128) bar (1, 1);
+}
Jakub
