Hi!
A recent unroller change results in the arg_types array initializing
loop in altivec_build_resolved_builtin being completely unrolled.
The callers ensure that for ALTIVEC_BUILTIN_VEC_VCMPGE_P all the 3
arguments are provided (i.e. n == 3), but the compiler doesn't know that
and emits -Wmaybe-uninitialized warning.
Fixed thusly, additionally simplified the code/made it more readable
with std::swap. Bootstrapped/regtested on powerpc64le-linux, preapproved by
Segher on IRC, committed to trunk.
2019-11-11 Jakub Jelinek <ja...@redhat.com>
PR bootstrap/92433
* config/rs6000/rs6000-c.c (altivec_build_resolved_builtin): Guard
ALTIVEC_BUILTIN_VEC_VCMPGE_P argument swapping with n == 3 check. Use
std::swap.
--- gcc/config/rs6000/rs6000-c.c.jj 2019-08-27 12:26:30.115019661 +0200
+++ gcc/config/rs6000/rs6000-c.c 2019-11-11 10:12:00.954282097 +0100
@@ -6076,14 +6076,14 @@ altivec_build_resolved_builtin (tree *ar
condition (LT vs. EQ, which is recognizable by bit 1 of the first
argument) is reversed. Patch the arguments here before building
the resolved CALL_EXPR. */
- if (desc->code == ALTIVEC_BUILTIN_VEC_VCMPGE_P
+ if (n == 3
+ && desc->code == ALTIVEC_BUILTIN_VEC_VCMPGE_P
&& desc->overloaded_code != ALTIVEC_BUILTIN_VCMPGEFP_P
&& desc->overloaded_code != VSX_BUILTIN_XVCMPGEDP_P)
{
- tree t;
- t = args[2], args[2] = args[1], args[1] = t;
- t = arg_type[2], arg_type[2] = arg_type[1], arg_type[1] = t;
-
+ std::swap (args[1], args[2]);
+ std::swap (arg_type[1], arg_type[2]);
+
args[0] = fold_build2 (BIT_XOR_EXPR, TREE_TYPE (args[0]), args[0],
build_int_cst (NULL_TREE, 2));
}
Jakub
