RISC-V: Fix ICE in riscv vector costs

The following code can result in ICE:
-march=rv64gcv --param riscv-autovec-lmul=dynamic -O3

char *jpeg_difference7_input_buf;
void jpeg_difference7(int *diff_buf) {
  unsigned width;
  int samp, Rb;
  while (--width) {
    Rb = samp = *jpeg_difference7_input_buf;
    *diff_buf++ = -(int)(samp + (long)Rb >> 1);
  }
}

One biggest_mode update missed in one branch and trigger assertion fail.
gcc_assert (biggest_size >= mode_size);

Tested On RV64 and no regression.

	PR target/114264

gcc/ChangeLog:

	* config/riscv/riscv-vector-costs.cc: Fix ICE

gcc/testsuite/ChangeLog:

	* gcc.dg/vect/costmodel/riscv/rvv/pr114264.c: New test.

Signed-off-by: demin.han <demin.han@starfivetech.com>

2 files changed, 17 insertions, 0 deletions

diff --git a/gcc/config/riscv/riscv-vector-costs.cc b/gcc/config/riscv/riscv-vector-costs.cc
index adf9c19..5ac8655 100644
--- a/gcc/config/riscv/riscv-vector-costs.cc
+++ b/gcc/config/riscv/riscv-vector-costs.cc
@@ -414,6 +414,8 @@ compute_local_live_ranges (
 				  auto *r = get_live_range (live_ranges, arg);
 				  gcc_assert (r);
 				  (*r).second = MAX (point, (*r).second);
+				  biggest_mode = get_biggest_mode (
+				    biggest_mode, TYPE_MODE (TREE_TYPE (arg)));
 				}
 			    }
 			  else
diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr114264.c b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr114264.c
new file mode 100644
index 0000000..7853f29
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr114264.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -ftree-vectorize --param=riscv-autovec-lmul=dynamic" } */
+
+char *jpeg_difference7_input_buf;
+void
+jpeg_difference7 (int *diff_buf)
+{
+  unsigned width;
+  int samp, Rb;
+  while (--width)
+    {
+      Rb = samp = *jpeg_difference7_input_buf;
+      *diff_buf++ = -(int) (samp + (long) Rb >> 1);
+    }
+}