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>
(cherry picked from commit be07dd9a96a7a6f8fb59c939eda84d74b54f8182)

diff --git a/gcc/builtins.cc b/gcc/builtins.cc
index a5f711a7b6a29d2e141eacb1d429e1eb4368536d..a387863558bcfceb27382265311eb582cc69890f 100644 (file)
--- a/gcc/builtins.cc
+++ b/gcc/builtins.cc
@@ -7800,11 +7800,17 @@ 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 058f6a24fe99c8c6c48dd4e080b137df4029fed9..f45927a908ad477613d222d02b63ca43ff5931b2 100644 (file)
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -15439,7 +15439,7 @@ 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
@@ -15494,7 +15494,7 @@ 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 21eac80819a541581a50f2e2e9f558efd9fbe2e9..9b96cb2325d45c784f3dcb535c7b0c5c4f501972 100644 (file)
--- a/gcc/internal-fn.cc
+++ b/gcc/internal-fn.cc
@@ -4024,9 +4024,14 @@ 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" } */
+}