[PATCH][AArch32]: Correct sdot RTL on aarch32

[Tamar Christina via Gcc-patches]

Hi All,

The RTL Generated from <sup>dot_prod<vsi2qi> is invalid as operand3 cannot be
written to, it's a normal input.  For the expand it's just another operand
but the caller does not expect it to be written to.

Bootstrapped Regtested on arm-none-linux-gnueabihf and no issues.

Ok for master? and backport to GCC 11, 10, 9?

Thanks,
Tamar

gcc/ChangeLog:

        * config/arm/neon.md (<sup>dot_prod<vsi2qi>): Drop statements.

--- inline copy of patch -- 
diff --git a/gcc/config/arm/neon.md b/gcc/config/arm/neon.md
index 
61d81646475ce3bf62ece2cec2faf0c1fe978ec1..9602e9993aeebf4ec620d105fd20f64498a3b851
 100644
--- a/gcc/config/arm/neon.md
+++ b/gcc/config/arm/neon.md
@@ -3067,13 +3067,7 @@ (define_expand "<sup>dot_prod<vsi2qi>"
                     DOTPROD)
                    (match_operand:VCVTI 3 "register_operand")))]
   "TARGET_DOTPROD"
-{
-  emit_insn (
-    gen_neon_<sup>dot<vsi2qi> (operands[3], operands[3], operands[1],
-                                operands[2]));
-  emit_insn (gen_rtx_SET (operands[0], operands[3]));
-  DONE;
-})
+)
 
 ;; Auto-vectorizer pattern for usdot
 (define_expand "usdot_prod<vsi2qi>"


-- 

diff --git a/gcc/config/arm/neon.md b/gcc/config/arm/neon.md
index 61d81646475ce3bf62ece2cec2faf0c1fe978ec1..9602e9993aeebf4ec620d105fd20f64498a3b851 100644
--- a/gcc/config/arm/neon.md
+++ b/gcc/config/arm/neon.md
@@ -3067,13 +3067,7 @@ (define_expand "<sup>dot_prod<vsi2qi>"
 		     DOTPROD)
 		    (match_operand:VCVTI 3 "register_operand")))]
   "TARGET_DOTPROD"
-{
-  emit_insn (
-    gen_neon_<sup>dot<vsi2qi> (operands[3], operands[3], operands[1],
-				 operands[2]));
-  emit_insn (gen_rtx_SET (operands[0], operands[3]));
-  DONE;
-})
+)
 
 ;; Auto-vectorizer pattern for usdot
 (define_expand "usdot_prod<vsi2qi>"