At least with -m32 you need -maltivec if you #include <altivec.h>.
gcc/testsuite/
* g++.target/powerpc/undef-bool-3.C: Add -maltivec to dg-options.
From-SVN: r271966
+2019-06-05 Segher Boessenkool <segher@kernel.crashing.org>
+
+ * g++.target/powerpc/undef-bool-3.C: Add -maltivec to dg-options.
+
2019-06-05 Martin Sebor <msebor@redhat.com>
* gcc.dg/weak/weak-19.c: New test.
/* { dg-do compile } */
-/* { dg-options "-O2 -std=c++11" } */
+/* { dg-options "-O2 -std=c++11 -maltivec" } */
/* Test to ensure that "bool" is not #define'd in altivec.h for C++ when
we require strict ANSI. We should compile without errors. */