[gcc r14-9380] RISC-V: Fix ICE in riscv vector costs

[Demin Han]

https://gcc.gnu.org/g:42187c6968af9907de1f9b7563d87de739857684

commit r14-9380-g42187c6968af9907de1f9b7563d87de739857684
Author: demin.han <demin.han@starfivetech.com>
Date:   Wed Mar 6 17:34:34 2024 +0800

    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>

Diff:
---
 gcc/config/riscv/riscv-vector-costs.cc                   |  2 ++
 gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr114264.c | 15 +++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/gcc/config/riscv/riscv-vector-costs.cc b/gcc/config/riscv/riscv-vector-costs.cc
index adf9c197df5..5ac8655b4d8 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 00000000000..7853f292af7
--- /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);
+    }
+}