PR optimization/6842

	* combine.c (combine_simplify_rtx) [SUBREG]: Don't ICE if VOIDmode
	operand subreg cannot be simplified.

	* gcc.dg/20020531-1.c: New test.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@54462 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ba8541b..fd4663b 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,11 @@
 2002-06-10  Jakub Jelinek  <jakub@redhat.com>
 
+       PR optimization/6842
+       * combine.c (combine_simplify_rtx) [SUBREG]: Don't ICE if VOIDmode
+       operand subreg cannot be simplified.
+
+2002-06-10  Jakub Jelinek  <jakub@redhat.com>
+
        * varasm.c (const_hash): Handle FDESC_EXPR like ADDR_EXPR.
        (compare_constant): Likewise.
        (output_addressed_constants): Likewise.

diff --git a/gcc/combine.c b/gcc/combine.c
index 11de1c7..0005e2a 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -3866,7 +3866,12 @@ combine_simplify_rtx (x, op0_mode, last, in_dest)
 
       /* simplify_subreg can't use gen_lowpart_for_combine.  */
       if (CONSTANT_P (SUBREG_REG (x))
-         && subreg_lowpart_offset (mode, op0_mode) == SUBREG_BYTE (x))
+         && subreg_lowpart_offset (mode, op0_mode) == SUBREG_BYTE (x)
+            /* Don't call gen_lowpart_for_combine if the inner mode
+               is VOIDmode and we cannot simplify it, as SUBREG without
+               inner mode is invalid.  */
+         && (GET_MODE (SUBREG_REG (x)) != VOIDmode
+             || gen_lowpart_common (mode, SUBREG_REG (x))))
        return gen_lowpart_for_combine (mode, SUBREG_REG (x));
 
       if (GET_MODE_CLASS (GET_MODE (SUBREG_REG (x))) == MODE_CC)

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f90d62d..a0a0de5 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -4,6 +4,8 @@
 
        * g++.dg/opt/vt1.C: New test.
 
+       * gcc.dg/20020531-1.c: New test.
+
 2002-06-07  Roger Sayle  <roger@eyesopen.com>
 
        * gcc.dg/20020607-2.c: New test case.

diff --git a/gcc/testsuite/gcc.dg/20020531-1.c b/gcc/testsuite/gcc.dg/20020531-1.c
new file mode 100644 (file)
index 0000000..397e2a2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/20020531-1.c
@@ -0,0 +1,21 @@
+/* PR optimization/6842
+   This testcase caused ICE when trying to optimize V8QI subreg of VOIDmode
+   CONST_DOUBLE.  */
+/* { dg-do compile { target i?86-*-* } } */
+/* { dg-options "-O2 -mmmx" } */
+
+typedef int __v8qi __attribute__ ((__mode__ (__V8QI__)));
+extern void abort (void);
+extern void exit (int);
+
+void foo (void)
+{
+  unsigned long long a = 0x0102030405060708LL;
+  unsigned long long b = 0x1020304050607080LL;
+  unsigned long long c;
+
+  c = (unsigned long long) __builtin_ia32_paddusb ((__v8qi) a, (__v8qi) b);
+  __builtin_ia32_emms ();
+  if (c != 0x1122334455667788)
+    abort ();
+}