[PATCH] RISC-V: Fix the V calling convention

[Palmer Dabbelt <palmer@rivosinc.com>]

The V registers are always clobbered on calls.

gcc/ChangeLog

	* config/riscv/riscv.cc (riscv_conditional_register_usage):
	Always mark the V registers as clobbered on calls.
---
 gcc/config/riscv/riscv.cc | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 675d92c0961..c18e61f4a03 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -5442,11 +5442,18 @@ riscv_conditional_register_usage (void)
   if (!TARGET_VECTOR)
     {
       for (int regno = V_REG_FIRST; regno <= V_REG_LAST; regno++)
-	fixed_regs[regno] = call_used_regs[regno] = 1;
+	fixed_regs[regno] = 1;
 
-      fixed_regs[VTYPE_REGNUM] = call_used_regs[VTYPE_REGNUM] = 1;
-      fixed_regs[VL_REGNUM] = call_used_regs[VL_REGNUM] = 1;
+      fixed_regs[VTYPE_REGNUM] = 1;
+      fixed_regs[VL_REGNUM] = 1;
     }
+
+  /* The standard ABIs all clobber the entire vector state on calls.  */
+  for (int regno = V_REG_FIRST; regno <= V_REG_LAST; regno++)
+    call_used_regs[regno] = 1;
+
+  call_used_regs[VTYPE_REGNUM] = 1;
+  call_used_regs[VL_REGNUM] = 1;
 }
 
 /* Return a register priority for hard reg REGNO.  */
-- 
2.34.1