crc: Error out on non-constant poly arguments for the crc builtins [PR120709]

These builtins requires a constant integer for the third argument but currently
there is assert rather than error. This fixes that and updates the documentation too.
Uses the same terms as was being used for the __builtin_prefetch arguments.

Bootstrapped and tested on x86_64-linux-gnu.

	PR middle-end/120709

gcc/ChangeLog:

	* builtins.cc (expand_builtin_crc_table_based): Error out
	instead of asserting the 3rd argument is an integer constant.
	* internal-fn.cc (expand_crc_optab_fn): Likewise.
	* doc/extend.texi (crc): Document requirement of the poly argument
	being a constant.

gcc/testsuite/ChangeLog:

	* gcc.dg/crc-non-cst-poly-1.c: New test.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>

diff --git a/gcc/builtins.cc b/gcc/builtins.cc
index a2ce37268107b1d4eb4cd44b1ce25ac292cb3a39..7f580a3145ff5580f94d5493bfaab76e8cebeae4 100644 (file)
--- a/gcc/builtins.cc
+++ b/gcc/builtins.cc
@@ -7799,11 +7799,17 @@ expand_builtin_crc_table_based (internal_fn fn, scalar_mode crc_mode,
 
   rtx op1 = expand_normal (rhs1);
   rtx op2 = expand_normal (rhs2);
-  gcc_assert (TREE_CODE (rhs3) == INTEGER_CST);
-  rtx op3 = gen_int_mode (TREE_INT_CST_LOW (rhs3), crc_mode);
+  rtx op3;
+  if (TREE_CODE (rhs3) != INTEGER_CST)
+    {
+      error ("third argument to %<crc%> builtins must be a constant");
+      op3 = const0_rtx;
+    }
+  else
+    op3 = convert_to_mode (crc_mode, expand_normal (rhs3), 0);
 
   if (CONST_INT_P (op2))
-    op2 = gen_int_mode (INTVAL (op2), crc_mode);
+    op2 = convert_to_mode (crc_mode, op2, 0);
 
   if (fn == IFN_CRC)
     expand_crc_table_based (target, op1, op2, op3, data_mode);

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 70adf2dab0a3efb4b0b4e323ab927f5d024bbdb9..a119ad31ea2e414c32ad5a19177fe23d60c5c4b7 100644 (file)
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -15553,7 +15553,7 @@ are 128-bit.  Only supported on targets when 128-bit types are supported.
 Returns the calculated 8-bit bit-reversed CRC using the initial CRC (8-bit),
 data (8-bit) and the polynomial (8-bit).
 @var{crc} is the initial CRC, @var{data} is the data and
-@var{poly} is the polynomial without leading 1.
+@var{poly} is the polynomial without leading 1. @var{poly} is required to be a compile-time constant.
 Table-based or clmul-based CRC may be used for the
 calculation, depending on the target architecture.
 @enddefbuiltin
@@ -15608,7 +15608,7 @@ is 32-bit.
 Returns the calculated 8-bit bit-forward CRC using the initial CRC (8-bit),
 data (8-bit) and the polynomial (8-bit).
 @var{crc} is the initial CRC, @var{data} is the data and
-@var{poly} is the polynomial without leading 1.
+@var{poly} is the polynomial without leading 1. @var{poly} is required to be a compile-time constant.
 Table-based or clmul-based CRC may be used for the
 calculation, depending on the target architecture.
 @enddefbuiltin

diff --git a/gcc/internal-fn.cc b/gcc/internal-fn.cc
index 3f4ac937367deedc27c5e13720de1bebd0322b84..39048d77d23b3c5422e786f23e4bb98614fef941 100644 (file)
--- a/gcc/internal-fn.cc
+++ b/gcc/internal-fn.cc
@@ -4031,9 +4031,14 @@ expand_crc_optab_fn (internal_fn fn, gcall *stmt, convert_optab optab)
   rtx dest = expand_expr (lhs, NULL_RTX, VOIDmode, EXPAND_WRITE);
   rtx crc = expand_normal (rhs1);
   rtx data = expand_normal (rhs2);
-  gcc_assert (TREE_CODE (rhs3) == INTEGER_CST);
-  rtx polynomial = gen_rtx_CONST_INT (TYPE_MODE (result_type),
-                                     TREE_INT_CST_LOW (rhs3));
+  rtx polynomial;
+  if (TREE_CODE (rhs3) != INTEGER_CST)
+    {
+      error ("third argument to %<crc%> builtins must be a constant");
+      polynomial = const0_rtx;
+    }
+  else
+    polynomial = convert_to_mode (TYPE_MODE (result_type), expand_normal (rhs3), 0);
 
   /* Use target specific expansion if it exists.
      Otherwise, generate table-based CRC.  */

diff --git a/gcc/testsuite/gcc.dg/crc-non-cst-poly-1.c b/gcc/testsuite/gcc.dg/crc-non-cst-poly-1.c
new file mode 100644 (file)
index 0000000..0c3d905
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/crc-non-cst-poly-1.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+/* PR middle-end/120709 */
+/* Make sure we don't ICE on a non-constant poly argument. */
+
+
+typedef unsigned char uint8_t;
+uint8_t crc8_data8(uint8_t crc, uint8_t data, uint8_t polynomial) {
+  return __builtin_rev_crc32_data8 (crc, data, polynomial); /* { dg-error "must be a constant" } */
+}