[gcc r14-5062] RISC-V: Use riscv_subword_address for atomic_test_and_set

[gcc r14-5062] RISC-V: Use riscv_subword_address for atomic_test_and_set

[Patrick O'Neill]

https://gcc.gnu.org/g:274c904471a11c493353a8b4f6e50d8fb7fef906

commit r14-5062-g274c904471a11c493353a8b4f6e50d8fb7fef906
Author: Patrick O'Neill <patrick@rivosinc.com>
Date:   Tue Oct 31 13:18:53 2023 -0700

    RISC-V: Use riscv_subword_address for atomic_test_and_set
    
    Other subword atomic patterns use riscv_subword_address to calculate
    the aligned address, shift amount, mask and !mask. atomic_test_and_set
    was implemented before the common function was added. After this patch
    all subword atomic patterns use riscv_subword_address.
    
    gcc/ChangeLog:
    
            * config/riscv/sync.md:  Use riscv_subword_address function to
            calculate the address and shift in atomic_test_and_set.
    
    Signed-off-by: Patrick O'Neill <patrick@rivosinc.com>

Diff:
---
 gcc/config/riscv/sync.md | 41 +++++++++++++++++------------------------
 1 file changed, 17 insertions(+), 24 deletions(-)

diff --git a/gcc/config/riscv/sync.md b/gcc/config/riscv/sync.md
index ec9d4b4f59ef..f05cccf1bef2 100644
--- a/gcc/config/riscv/sync.md
+++ b/gcc/config/riscv/sync.md
@@ -504,43 +504,36 @@
    (set (attr "length") (const_int 28))])
 
 (define_expand "atomic_test_and_set"
-  [(match_operand:QI 0 "register_operand" "")     ;; bool output
+  [(match_operand:QI 0 "register_operand" "")    ;; bool output
    (match_operand:QI 1 "memory_operand" "+A")    ;; memory
-   (match_operand:SI 2 "const_int_operand" "")]   ;; model
+   (match_operand:SI 2 "const_int_operand" "")]  ;; model
   "TARGET_ATOMIC"
 {
   /* We have no QImode atomics, so use the address LSBs to form a mask,
      then use an aligned SImode atomic.  */
-  rtx result = operands[0];
+  rtx old = gen_reg_rtx (SImode);
   rtx mem = operands[1];
   rtx model = operands[2];
-  rtx addr = force_reg (Pmode, XEXP (mem, 0));
-
-  rtx aligned_addr = gen_reg_rtx (Pmode);
-  emit_move_insn (aligned_addr, gen_rtx_AND (Pmode, addr, GEN_INT (-4)));
+  rtx set = gen_reg_rtx (QImode);
+  rtx aligned_mem = gen_reg_rtx (SImode);
+  rtx shift = gen_reg_rtx (SImode);
 
-  rtx aligned_mem = change_address (mem, SImode, aligned_addr);
-  set_mem_alias_set (aligned_mem, 0);
+  /* Unused.  */
+  rtx _mask = gen_reg_rtx (SImode);
+  rtx _not_mask = gen_reg_rtx (SImode);
 
-  rtx offset = gen_reg_rtx (SImode);
-  emit_move_insn (offset, gen_rtx_AND (SImode, gen_lowpart (SImode, addr),
-				       GEN_INT (3)));
+  riscv_subword_address (mem, &aligned_mem, &shift, &_mask, &_not_mask);
 
-  rtx tmp = gen_reg_rtx (SImode);
-  emit_move_insn (tmp, GEN_INT (1));
+  emit_move_insn (set, GEN_INT (1));
+  rtx shifted_set = gen_reg_rtx (SImode);
+  riscv_lshift_subword (QImode, set, shift, &shifted_set);
 
-  rtx shmt = gen_reg_rtx (SImode);
-  emit_move_insn (shmt, gen_rtx_ASHIFT (SImode, offset, GEN_INT (3)));
+  emit_insn (gen_atomic_fetch_orsi (old, aligned_mem, shifted_set, model));
 
-  rtx word = gen_reg_rtx (SImode);
-  emit_move_insn (word, gen_rtx_ASHIFT (SImode, tmp,
-					gen_lowpart (QImode, shmt)));
+  emit_move_insn (old, gen_rtx_ASHIFTRT (SImode, old,
+					 gen_lowpart (QImode, shift)));
 
-  tmp = gen_reg_rtx (SImode);
-  emit_insn (gen_atomic_fetch_orsi (tmp, aligned_mem, word, model));
+  emit_move_insn (operands[0], gen_lowpart (QImode, old));
 
-  emit_move_insn (gen_lowpart (SImode, result),
-		  gen_rtx_LSHIFTRT (SImode, tmp,
-				    gen_lowpart (QImode, shmt)));
   DONE;
 })