From b51d3b1af24758534e5a8f3a52a56106b935c485 Mon Sep 17 00:00:00 2001
From: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date: Wed, 31 May 2023 11:23:23 +0100
Subject: [PATCH 059/157] [Backport][SME] aarch64: Simplify output template
 emission code for a few patterns

Reference: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=11bd9b1f8133fc07c267e6d1aee8b01e06c7a750

If the output code for a define_insn just does a switch (which_alternative) with no other computation we can almost always
replace it with more compact MD syntax for each alternative in a mult-alternative '@' block.
This patch cleans up some such patterns in the aarch64 backend, making them shorter and more concise.
No behavioural change intended.

Bootstrapped and tested on aarch64-none-linux-gnu.

gcc/ChangeLog:

	* config/aarch64/aarch64-simd.md (*aarch64_simd_mov<VDMOV:mode>): Rewrite
	output template to avoid explicit switch on which_alternative.
	(*aarch64_simd_mov<VQMOV:mode>): Likewise.
	(and<mode>3): Likewise.
	(ior<mode>3): Likewise.
	* config/aarch64/aarch64.md (*mov<mode>_aarch64): Likewise.
---
 gcc/config/aarch64/aarch64-simd.md | 97 +++++++++---------------------
 gcc/config/aarch64/aarch64.md      | 42 ++++---------
 2 files changed, 40 insertions(+), 99 deletions(-)

diff --git a/gcc/config/aarch64/aarch64-simd.md b/gcc/config/aarch64/aarch64-simd.md
index ef7fc4ecb..2d688edf5 100644
--- a/gcc/config/aarch64/aarch64-simd.md
+++ b/gcc/config/aarch64/aarch64-simd.md
@@ -122,28 +122,16 @@
   "TARGET_FLOAT
    && (register_operand (operands[0], <MODE>mode)
        || aarch64_simd_reg_or_zero (operands[1], <MODE>mode))"
-{
-   switch (which_alternative)
-     {
-     case 0: return "ldr\t%d0, %1";
-     case 1: return "str\txzr, %0";
-     case 2: return "str\t%d1, %0";
-     case 3:
-       if (TARGET_SIMD)
-	 return "mov\t%0.<Vbtype>, %1.<Vbtype>";
-       return "fmov\t%d0, %d1";
-     case 4:
-       if (TARGET_SIMD)
-	 return "umov\t%0, %1.d[0]";
-       return "fmov\t%x0, %d1";
-     case 5: return "fmov\t%d0, %1";
-     case 6: return "mov\t%0, %1";
-     case 7:
-	return aarch64_output_simd_mov_immediate (operands[1], 64);
-     case 8: return "fmov\t%d0, xzr";
-     default: gcc_unreachable ();
-     }
-}
+  "@
+   ldr\t%d0, %1
+   str\txzr, %0
+   str\t%d1, %0
+   * return TARGET_SIMD ? \"mov\t%0.<Vbtype>, %1.<Vbtype>\" : \"fmov\t%d0, %d1\";
+   * return TARGET_SIMD ? \"umov\t%0, %1.d[0]\" : \"fmov\t%x0, %d1\";
+   fmov\t%d0, %1
+   mov\t%0, %1
+   * return aarch64_output_simd_mov_immediate (operands[1], 64);
+   fmov\t%d0, xzr"
   [(set_attr "type" "neon_load1_1reg<q>, store_8, neon_store1_1reg<q>,\
 		     neon_logic<q>, neon_to_gp<q>, f_mcr,\
 		     mov_reg, neon_move<q>, f_mcr")
@@ -158,29 +146,16 @@
   "TARGET_FLOAT
    && (register_operand (operands[0], <MODE>mode)
        || aarch64_simd_reg_or_zero (operands[1], <MODE>mode))"
-{
-  switch (which_alternative)
-    {
-    case 0:
-	return "ldr\t%q0, %1";
-    case 1:
-	return "stp\txzr, xzr, %0";
-    case 2:
-	return "str\t%q1, %0";
-    case 3:
-	return "mov\t%0.<Vbtype>, %1.<Vbtype>";
-    case 4:
-    case 5:
-    case 6:
-	return "#";
-    case 7:
-	return aarch64_output_simd_mov_immediate (operands[1], 128);
-    case 8:
-	return "fmov\t%d0, xzr";
-    default:
-	gcc_unreachable ();
-    }
-}
+  "@
+   ldr\t%q0, %1
+   stp\txzr, xzr, %0
+   str\t%q1, %0
+   mov\t%0.<Vbtype>, %1.<Vbtype>
+   #
+   #
+   #
+   * return aarch64_output_simd_mov_immediate (operands[1], 128);
+   fmov\t%d0, xzr"
   [(set_attr "type" "neon_load1_1reg<q>, store_16, neon_store1_1reg<q>,\
 		     neon_logic<q>, multiple, multiple,\
 		     multiple, neon_move<q>, fmov")
@@ -1004,18 +979,10 @@
 	(and:VDQ_I (match_operand:VDQ_I 1 "register_operand" "w,0")
 		   (match_operand:VDQ_I 2 "aarch64_reg_or_bic_imm" "w,Db")))]
   "TARGET_SIMD"
-  {
-    switch (which_alternative)
-      {
-      case 0:
-	return "and\t%0.<Vbtype>, %1.<Vbtype>, %2.<Vbtype>";
-      case 1:
-	return aarch64_output_simd_mov_immediate (operands[2], <bitsize>,
-						  AARCH64_CHECK_BIC);
-      default:
-	gcc_unreachable ();
-      }
-  }
+  "@
+   and\t%0.<Vbtype>, %1.<Vbtype>, %2.<Vbtype>
+   * return aarch64_output_simd_mov_immediate (operands[2], <bitsize>,\
+					       AARCH64_CHECK_BIC);"
   [(set_attr "type" "neon_logic<q>")]
 )
 
@@ -1025,18 +992,10 @@
 	(ior:VDQ_I (match_operand:VDQ_I 1 "register_operand" "w,0")
 		   (match_operand:VDQ_I 2 "aarch64_reg_or_orr_imm" "w,Do")))]
   "TARGET_SIMD"
-  {
-    switch (which_alternative)
-      {
-      case 0:
-	return "orr\t%0.<Vbtype>, %1.<Vbtype>, %2.<Vbtype>";
-      case 1:
-	return aarch64_output_simd_mov_immediate (operands[2], <bitsize>,
-						  AARCH64_CHECK_ORR);
-      default:
-	gcc_unreachable ();
-      }
-  }
+  "@
+   orr\t%0.<Vbtype>, %1.<Vbtype>, %2.<Vbtype>
+   * return aarch64_output_simd_mov_immediate (operands[2], <bitsize>,\
+					       AARCH64_CHECK_ORR);"
   [(set_attr "type" "neon_logic<q>")]
 )
 
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index c0cc91756..7454a5c77 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -1198,36 +1198,18 @@
 	(match_operand:SHORT 1 "aarch64_mov_operand"  " r,M,D<hq>,Usv,m,m,rZ,w,w,rZ,w"))]
   "(register_operand (operands[0], <MODE>mode)
     || aarch64_reg_or_zero (operands[1], <MODE>mode))"
-{
-   switch (which_alternative)
-     {
-     case 0:
-       return "mov\t%w0, %w1";
-     case 1:
-       return "mov\t%w0, %1";
-     case 2:
-       return aarch64_output_scalar_simd_mov_immediate (operands[1],
-							<MODE>mode);
-     case 3:
-       return aarch64_output_sve_cnt_immediate (\"cnt\", \"%x0\", operands[1]);
-     case 4:
-       return "ldr<size>\t%w0, %1";
-     case 5:
-       return "ldr\t%<size>0, %1";
-     case 6:
-       return "str<size>\t%w1, %0";
-     case 7:
-       return "str\t%<size>1, %0";
-     case 8:
-       return TARGET_SIMD ? "umov\t%w0, %1.<v>[0]" : "fmov\t%w0, %s1";
-     case 9:
-       return TARGET_SIMD ? "dup\t%0.<Vallxd>, %w1" : "fmov\t%s0, %w1";
-     case 10:
-       return TARGET_SIMD ? "dup\t%<Vetype>0, %1.<v>[0]" : "fmov\t%s0, %s1";
-     default:
-       gcc_unreachable ();
-     }
-}
+  "@
+   mov\t%w0, %w1
+   mov\t%w0, %1
+   * return aarch64_output_scalar_simd_mov_immediate (operands[1], <MODE>mode);
+   * return aarch64_output_sve_cnt_immediate (\"cnt\", \"%x0\", operands[1]);
+   ldr<size>\t%w0, %1
+   ldr\t%<size>0, %1
+   str<size>\t%w1, %0
+   str\t%<size>1, %0
+   * return TARGET_SIMD ? \"umov\t%w0, %1.<v>[0]\" : \"fmov\t%w0, %s1\";
+   * return TARGET_SIMD ? \"dup\t%0.<Vallxd>, %w1\" : \"fmov\t%s0, %w1\";
+   * return TARGET_SIMD ? \"dup\t%<Vetype>0, %1.<v>[0]\" : \"fmov\t%s0, %s1\";"
   ;; The "mov_imm" type for CNT is just a placeholder.
   [(set_attr "type" "mov_reg,mov_imm,neon_move,mov_imm,load_4,load_4,store_4,
 		     store_4,neon_to_gp<q>,neon_from_gp<q>,neon_dup")
-- 
2.33.0