GCC Maintainers:
I have addressed Segher's concerns regarding the range checking of the
argument. The following is the updated patch.
The regression testing for the patch was done on GCC mainline on
powerpc64le-unknown-linux-gnu (Power 8 LE)
with no regressions. Additional hand testing was done on the following
test cases to verify the range checking was working.
vec_splat_u8 (0xfffffffe);
vec_splat_u8 (0x7e);
vec_splat_u8 (0xfe);
vec_splat_u16 (0xfffffffe);
vec_splat_u16 (0x7ffe);
vec_splat_u16 (0xfffe);
vec_splat_u16 (-2);
vec_splat_u32 (0xfffffffe);
vec_splat_u32 (0xeffffffe);
vec_splat_s32 (16);
vec_splat_s32 (15);
vec_splat_s32 (-16);
vec_splat_s32 (-17);
vec_splat_s8 (16);
vec_splat_s8 (15);
vec_splat_s8 (1);
vec_splat_s8 (-1);
vec_splat_s8 (-16);
vec_splat_s8 (-17);
Please let me know if the patch looks OK for the GCC 7 branch.
Carl Love
--------------------------------------------------
gcc/ChangeLog:
2018-04-17 Carl Love <c...@us.ibm.com>
PR target/83402
* config/rs6000/rs6000-c.c (rs6000_gimple_fold_builtin): Add
size check for arg0.
---
gcc/config/rs6000/rs6000.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index a0c9b5c..6b8039d 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -16574,10 +16574,23 @@ rs6000_gimple_fold_builtin
(gimple_stmt_iterator *gsi)
case ALTIVEC_BUILTIN_VSPLTISH:
case ALTIVEC_BUILTIN_VSPLTISW:
{
+ int size;
+
+ if (fn_code == ALTIVEC_BUILTIN_VSPLTISB)
+ size = 8;
+ else if (fn_code == ALTIVEC_BUILTIN_VSPLTISH)
+ size = 16;
+ else
+ size = 32;
+
arg0 = gimple_call_arg (stmt, 0);
lhs = gimple_call_lhs (stmt);
- /* Only fold the vec_splat_*() if arg0 is constant. */
- if (TREE_CODE (arg0) != INTEGER_CST)
+
+ /* Only fold the vec_splat_*() if the lower bits of arg 0 is
a
+ 5-bit signed constant in range -16 to +15. */
+ if (TREE_CODE (arg0) != INTEGER_CST
+ || !IN_RANGE (sext_hwi(TREE_INT_CST_LOW (arg0), size),
+ -16, 15))
return false;
gimple_seq stmts = NULL;
location_t loc = gimple_location (stmt);
--
2.7.4
