[gcc r13-5263] x86: Check invalid third argument to __builtin_ia32_prefetch

[gcc r13-5263] x86: Check invalid third argument to __builtin_ia32_prefetch

[H.J. Lu]

https://gcc.gnu.org/g:77a67e3a9294c825ac1a2b205fbb266e7c29e82b

commit r13-5263-g77a67e3a9294c825ac1a2b205fbb266e7c29e82b
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Wed Jan 18 11:08:14 2023 -0800

    x86: Check invalid third argument to __builtin_ia32_prefetch
    
    Check invalid third argument to __builtin_ia32_prefetch when expaning
    __builtin_ia32_prefetch to avoid ICE later.
    
    gcc/
    
            PR target/108436
            * config/i386/i386-expand.cc (ix86_expand_builtin): Check
            invalid third argument to __builtin_ia32_prefetch.
    
    gcc/testsuite/
    
            * gcc.target/i386/pr108436.c: New test.

Diff:
---
 gcc/config/i386/i386-expand.cc           | 12 ++++++++++++
 gcc/testsuite/gcc.target/i386/pr108436.c | 15 +++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 54f700cd09d..e2e2d28bb47 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -13175,6 +13175,12 @@ ix86_expand_builtin (tree exp, rtx target, rtx subtarget,
 
 	if (INTVAL (op3) == 1)
 	  {
+	    if (INTVAL (op2) < 2 || INTVAL (op2) > 3)
+	      {
+		error ("invalid third argument");
+		return const0_rtx;
+	      }
+
 	    if (TARGET_64BIT && TARGET_PREFETCHI
 		&& local_func_symbolic_operand (op0, GET_MODE (op0)))
 	      emit_insn (gen_prefetchi (op0, op2));
@@ -13195,6 +13201,12 @@ ix86_expand_builtin (tree exp, rtx target, rtx subtarget,
 		op0 = copy_addr_to_reg (op0);
 	      }
 
+	    if (INTVAL (op2) < 0 || INTVAL (op2) > 3)
+	      {
+		warning (0, "invalid third argument to %<__builtin_ia32_prefetch%>; using zero");
+		op2 = const0_rtx;
+	      }
+
 	    if (TARGET_3DNOW || TARGET_PREFETCH_SSE
 		|| TARGET_PRFCHW || TARGET_PREFETCHWT1)
 	      emit_insn (gen_prefetch (op0, op1, op2));
diff --git a/gcc/testsuite/gcc.target/i386/pr108436.c b/gcc/testsuite/gcc.target/i386/pr108436.c
new file mode 100644
index 00000000000..d51f25863a5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr108436.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-mprefetchi" } */
+
+int
+foo (int a)
+{
+  return a + 1;
+}
+
+void
+bad (int *p)
+{
+  __builtin_ia32_prefetch (p, 0, 4, 0);   /* { dg-warning "invalid third argument to '__builtin_ia32_prefetch'; using zero" } */
+  __builtin_ia32_prefetch (foo, 0, 4, 1);   /* { dg-error "invalid third argument" } */
+}