[PATCH v2] RISC-V: Disable misaligned vector access in hook riscv_slow_unaligned_access[PR115862]

[Li Xu]

From: xuli <xu...@eswincomputing.com>

The reason is that in the following code, icode = movmisalignv8si has
already been rejected by TARGET_VECTOR_MISALIGN_SUPPORTED, but it is
allowed by targetm.slow_unaligned_access,which is contradictory.

(((icode = optab_handler (movmisalign_optab, mode))
           != CODE_FOR_nothing)
          || targetm.slow_unaligned_access (mode, align))

misaligned vector access should be enabled by -mno-vector-strict-align option.

PR Target/115862

gcc/ChangeLog:

        * config/riscv/riscv.cc (riscv_slow_unaligned_access): Disable vector 
misalign.

Signed-off-by: Li Xu <xu...@eswincomputing.com>
---
 gcc/config/riscv/riscv.cc                     |  5 +-
 .../gcc.target/riscv/rvv/base/pr115862.c      | 52 +++++++++++++++++++
 2 files changed, 55 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/pr115862.c

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 61fa74e9322..16b210f323e 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -10269,9 +10269,10 @@ riscv_cannot_copy_insn_p (rtx_insn *insn)
 /* Implement TARGET_SLOW_UNALIGNED_ACCESS.  */
 
 static bool
-riscv_slow_unaligned_access (machine_mode, unsigned int)
+riscv_slow_unaligned_access (machine_mode mode, unsigned int)
 {
-  return riscv_slow_unaligned_access_p;
+  return VECTOR_MODE_P (mode) ? TARGET_VECTOR_MISALIGN_SUPPORTED
+                             : riscv_slow_unaligned_access_p;
 }
 
 static bool
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/base/pr115862.c 
b/gcc/testsuite/gcc.target/riscv/rvv/base/pr115862.c
new file mode 100644
index 00000000000..3cbc3c3a0ea
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/base/pr115862.c
@@ -0,0 +1,52 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=rv64gcv_zvl512b -mabi=lp64d" } */
+
+struct mallinfo2
+{
+  int arena;
+  int ordblks;
+  int smblks;
+  int hblks;
+  int hblkhd;
+  int usmblks;
+  int fsmblks;
+  int uordblks;
+  int fordblks;
+  int keepcost;
+};
+
+struct mallinfo
+{
+  int arena;
+  int ordblks;
+  int smblks;
+  int hblks;
+  int hblkhd;
+  int usmblks;
+  int fsmblks;
+  int uordblks;
+  int fordblks;
+  int keepcost;
+};
+
+struct mallinfo
+__libc_mallinfo (void)
+{
+  struct mallinfo m;
+  struct mallinfo2 m2;
+
+  m.arena = m2.arena;
+  m.ordblks = m2.ordblks;
+  m.smblks = m2.smblks;
+  m.hblks = m2.hblks;
+  m.hblkhd = m2.hblkhd;
+  m.usmblks = m2.usmblks;
+  m.fsmblks = m2.fsmblks;
+  m.uordblks = m2.uordblks;
+  m.fordblks = m2.fordblks;
+  m.keepcost = m2.keepcost;
+
+  return m;
+}
+
+/* { dg-final { scan-assembler {vle32\.v} } } */
-- 
2.17.1