[rs6000] fix PR 88100, range check for vec_splat_{su}{8,16,32}

GCC revision 259524 implemented range check for the vec_splat_{su}{8,16,32}
builtins.  However, as a consequence of the implementation, the range check
is not done correctly for the expected vspltis[bhw] instructions.  The result
is that we may not get a valid error message if the valid range of the data
is exceeded.

Although the input of the function prototype of vec_splat_{su}{8,16,32} is
const int, the actual data usage range is limited to the data range of 5 bits
signed.  We should limit the int_cst.val[0] data to the 5 bit signed data range
without any modification in the input arg0 parameter.  However, the sext_hwi
function intercepts the data of TREE_INT_CST_LOW (arg0) as size bits in the
sext_hwi (TREE_INT_CST_LOW (arg0), size) statement.  This will cause some of
the excess data to fall within the range of 5 bits signed, so that the correct
diagnostic information cannot be generated, we need to remove the sext_hwi to
ensure that the input data has not been modified.

This patch fix range check for the vec_splat_s[8,16,32] builtins.  The argument
must be a 5-bit const int as specified for the vspltis[bhw] instructions.

for gcc/ChangeLog

	PR target/88100
	* gcc/config/rs6000/rs6000.c (rs6000_gimple_fold_builtin)
	<case ALTIVEC_BUILTIN_VSPLTISB, ALTIVEC_BUILTIN_VSPLTISH,
	ALTIVEC_BUILTIN_VSPLTISW>: Don't convert the operand before
	range checking it.

for gcc/testsuite/ChangeLog

	PR target/88100
	* gcc/testsuite/gcc.target/powerpc/pr88100.c: New testcase.

From-SVN: r269033

gcc/ChangeLog

@@ -1,3 +1,11 @@
+2019-02-20  Li Jia He  <helijia@linux.ibm.com>
+
+	PR target/88100
+	* gcc/config/rs6000/rs6000.c (rs6000_gimple_fold_builtin)
+	<case ALTIVEC_BUILTIN_VSPLTISB, ALTIVEC_BUILTIN_VSPLTISH,
+	ALTIVEC_BUILTIN_VSPLTISW>: Don't convert the operand before
+	range checking it.
+
 2019-02-19  Jonathan Wakely  <jwakely@redhat.com>
 
 	* config/gcn/gcn.c (print_operand): Fix typo.

gcc/config/rs6000/rs6000.c

@@ -16105,22 +16105,13 @@ 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 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))
+	    || !IN_RANGE (TREE_INT_CST_LOW (arg0), -16, 15))
 	  return false;
 	gimple_seq stmts = NULL;
 	location_t loc = gimple_location (stmt);

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2019-02-20  Li Jia He  <helijia@linux.ibm.com>
+
+	PR target/88100
+	* gcc/testsuite/gcc.target/powerpc/pr88100.c: New testcase.
+
 2019-02-19  Wilco Dijkstra  <wdijkstr@arm.com>
 
 	* gcc.target/arm/pr88850.c: Block -mfloat-abi override.

gcc/testsuite/gcc.target/powerpc/pr88100.c

@@ -0,0 +1,44 @@
+/* PR88100.  Verify that rs6000 gimple-folding code handles the
+   vec_splat_{su}{8,16,32} invalid data properly. */
+
+/* { dg-do compile } */
+/* { dg-require-effective-target powerpc_altivec_ok } */
+/* { dg-options "-maltivec" } */
+
+#include <altivec.h>
+
+vector unsigned char
+splatu1 (void)
+{
+  return vec_splat_u8(0x100);/* { dg-error "argument 1 must be a 5-bit signed literal" } */
+}
+
+vector unsigned short
+splatu2 (void)
+{
+  return vec_splat_u16(0x10000);/* { dg-error "argument 1 must be a 5-bit signed literal" } */
+}
+
+vector unsigned int
+splatu3 (void)
+{
+  return vec_splat_u32(0x10000000);/* { dg-error "argument 1 must be a 5-bit signed literal" } */
+}
+
+vector signed char
+splats1 (void)
+{
+  return vec_splat_s8(0x100);/* { dg-error "argument 1 must be a 5-bit signed literal" } */
+}
+
+vector signed short
+splats2 (void)
+{
+  return vec_splat_s16(0x10000);/* { dg-error "argument 1 must be a 5-bit signed literal" } */
+}
+
+vector signed int
+splats3 (void)
+{
+  return vec_splat_s32(0x10000000);/* { dg-error "argument 1 must be a 5-bit signed literal" } */
+}