[PATCH] RISC-V: If -m[no-]strict-align is not passed, assume its value from -mtune

[Palmer Dabbelt]

From: Andrew Waterman <and...@sifive.com>

2017-11-03  Andrew Waterman  <and...@sifive.com>

        * config/riscv/riscv.c (riscv_option_override): Conditionally set
        TARGET_STRICT_ALIGN based upon -mtune argument.
---
 gcc/config/riscv/riscv.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/gcc/config/riscv/riscv.c b/gcc/config/riscv/riscv.c
index b81a2d29fbfd..f0b05d7eaeda 100644
--- a/gcc/config/riscv/riscv.c
+++ b/gcc/config/riscv/riscv.c
@@ -3772,9 +3772,13 @@ riscv_option_override (void)
 
   /* Use -mtune's setting for slow_unaligned_access, even when optimizing
      for size.  For architectures that trap and emulate unaligned accesses,
-     the performance cost is too great, even for -Os.  */
-  riscv_slow_unaligned_access_p = (cpu->tune_info->slow_unaligned_access
-                                  || TARGET_STRICT_ALIGN);
+     the performance cost is too great, even for -Os.  Similarly, if
+     -m[no-]strict-align is left unspecified, heed -mtune's advice.  */
+  riscv_slow_unaligned_access = (cpu->tune_info->slow_unaligned_access
+                                || TARGET_STRICT_ALIGN);
+  if ((target_flags_explicit & MASK_STRICT_ALIGN) == 0
+      && cpu->tune_info->slow_unaligned_access)
+    target_flags |= MASK_STRICT_ALIGN;
 
   /* If the user hasn't specified a branch cost, use the processor's
      default.  */
-- 
2.13.6