merge revision(s) 43ff0c2c488c80aaf83b486d45bcd4a92ebe3848: [Backport #19299]

YJIT: Fix `yield` into block with >=30 locals on ARM

	It's a register spill issue. Fix by moving the Qnil fill snippet to
	after registers are released.

	[Bug #19299]
	---
	 test/ruby/test_yjit.rb | 14 ++++++++++++++
	 yjit/src/codegen.rs    | 29 ++++++++++++++---------------
	 2 files changed, 28 insertions(+), 15 deletions(-)

test/ruby/test_yjit.rb

@@ -1028,6 +1028,20 @@ class TestYJIT < Test::Unit::TestCase
     RUBY
   end
 
+  def test_invokeblock_many_locals
+    # [Bug #19299]
+    assert_compiles(<<~'RUBY', result: :ok)
+      def foo
+        yield
+      end
+
+      foo do
+        a1=a2=a3=a4=a5=a6=a7=a8=a9=a10=a11=a12=a13=a14=a15=a16=a17=a18=a19=a20=a21=a22=a23=a24=a25=a26=a27=a28=a29=a30 = :ok
+        a30
+      end
+    RUBY
+  end
+
   private
 
   def code_gc_helpers

version.h

@@ -11,7 +11,7 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 0
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 6
+#define RUBY_PATCHLEVEL 7
 
 #include "ruby/version.h"
 #include "ruby/internal/abi.h"

yjit/src/codegen.rs

@@ -4455,19 +4455,6 @@ fn gen_push_frame(
     };
     asm.store(Opnd::mem(64, sp, SIZEOF_VALUE_I32 * -2), specval);
 
-    // Arm requires another register to load the immediate value of Qnil before storing it.
-    // So doing this after releasing the register for specval to avoid register spill.
-    let num_locals = frame.local_size;
-    if num_locals > 0 {
-        asm.comment("initialize locals");
-
-        // Initialize local variables to Qnil
-        for i in 0..num_locals {
-            let offs = (SIZEOF_VALUE as i32) * (i - num_locals - 3);
-            asm.store(Opnd::mem(64, sp, offs), Qnil.into());
-        }
-    }
-
     // Write env flags at sp[-1]
     // sp[-1] = frame_type;
     asm.store(Opnd::mem(64, sp, SIZEOF_VALUE_I32 * -1), frame.frame_type.into());
@@ -4505,6 +4492,20 @@ fn gen_push_frame(
     asm.mov(cfp_opnd(RUBY_OFFSET_CFP_SELF), frame.recv);
     asm.mov(cfp_opnd(RUBY_OFFSET_CFP_BLOCK_CODE), 0.into());
 
+    // This Qnil fill snippet potentially requires 2 more registers on Arm, one for Qnil and
+    // another for calculating the address in case there are a lot of local variables. So doing
+    // this after releasing the register for specval and the receiver to avoid register spill.
+    let num_locals = frame.local_size;
+    if num_locals > 0 {
+        asm.comment("initialize locals");
+
+        // Initialize local variables to Qnil
+        for i in 0..num_locals {
+            let offs = (SIZEOF_VALUE as i32) * (i - num_locals - 3);
+            asm.store(Opnd::mem(64, sp, offs), Qnil.into());
+        }
+    }
+
     if set_sp_cfp {
         // Saving SP before calculating ep avoids a dependency on a register
         // However this must be done after referencing frame.recv, which may be SP-relative
@@ -4778,8 +4779,6 @@ fn gen_return_branch(
     }
 }
 
-
-
 /// Pushes arguments from an array to the stack that are passed with a splat (i.e. *args)
 /// It optimistically compiles to a static size that is the exact number of arguments
 /// needed for the function.