bpf: fix cbranch miscompilation in CPUv1 [PR122141]

As diagnosed by Andrew in the linked PR, when reversing the branch
condition to work around lack of some cbranch instructions, we must
use swap_condition rather than reverse_condition.

	PR target/122141

gcc/

	* config/bpf/bpf.cc (bpf_expand_cbranch): Use swap_condition
	rather than reverse_condition when reversing jump condition to
	work around missing instructions in very old BPF ISAs.

gcc/testsuite/

	* gcc.target/bpf/pr122141-1.c: New.
	* gcc.target/bpf/pr122141-2.c: New.

Suggested-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>

gcc/config/bpf/bpf.cc

@@ -444,7 +444,7 @@ bpf_expand_cbranch (machine_mode mode, rtx *operands)
   if ((code == LT || code == LE || code == LTU || code == LEU))
     {
       /* Reverse the condition.  */
-      PUT_CODE (operands[0], reverse_condition (code));
+      PUT_CODE (operands[0], swap_condition (code));
 
       /* Swap the operands, and ensure that the first is a register.  */
       if (!register_operand (operands[2], mode))

gcc/testsuite/gcc.target/bpf/pr122141-1.c

@@ -0,0 +1,11 @@
+/* PR122141 miscompilation when j(s)l[te] unavailable.  */
+/* { dg-do compile } */
+/* { dg-options "-O2 -mcpu=v1 -masm=normal" } */
+
+int
+f(long a, long b)
+{
+  return a > b ? 2 : 3;
+}
+
+/* { dg-final { scan-assembler "jsge\t%r2,%r1" } } */

gcc/testsuite/gcc.target/bpf/pr122141-2.c

@@ -0,0 +1,11 @@
+/* PR122141 miscompilation when j(s)l[te] unavailable.  */
+/* { dg-do compile } */
+/* { dg-options "-O2 -mcpu=v1 -masm=normal" } */
+
+int
+g(unsigned long a, unsigned long b)
+{
+  return a >= b ? 4 : 5;
+}
+
+/* { dg-final { scan-assembler "jgt\t%r2,%r1" } } */