From 4b3255c08c87cf604e55eec57ae434b755c2513c Mon Sep 17 00:00:00 2001
From: ketmar <ketmar@ketmar.no-ip.org>
Date: Sat, 20 Nov 2021 23:22:47 +0000
Subject: [PATCH] egra: use `naked` `memFillDW()`

FossilOrigin-Name: 4c79cdac61b3b43a53c539bd4737dcfefb926ba80e597e4e55d23e6fd7631aaa
---
 egra/gfx/base.d | 34 ++++++++++++++++++++++------------
 1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/egra/gfx/base.d b/egra/gfx/base.d
index 1a79b99..db36fed 100644
--- a/egra/gfx/base.d
+++ b/egra/gfx/base.d
@@ -1413,14 +1413,23 @@ public void gxDrawLine() (in auto ref GxPoint p0, auto ref GxPoint p1, in uint c
 
 
 // ////////////////////////////////////////////////////////////////////////// //
+version (DigitalMars) {
+  version(X86) {
+    version = EGRA_USE_SSE_MEMFILL_DW;
+  }
+}
 // size is in dwords
-version(X86) {
+
+version(EGRA_USE_SSE_MEMFILL_DW) {
+// for x86 naked functions, DMD will pass last arg in EAX
 public void memFillDW (void* mptr, in uint value, in int count) nothrow @trusted @nogc {
   asm nothrow @trusted @nogc {
-    mov   EDX,EDI;
-    mov   EDI,[mptr];
-    mov   EAX,[value];
-    mov   ECX,[count];
+    naked;
+    mov   ECX,EAX;         // ECX=count (because last arg is in EAX)
+    mov   EAX,SS:[ESP+8];  // mptr
+    mov   SS:[ESP+8],EDI;  // save EDI
+    mov   EDI,EAX;         // EDI=mptr
+    mov   EAX,SS:[ESP+4];  // EAX=value
     cmp   ECX,0;
     jle   done;
     test  EDI,0x03;
@@ -1445,25 +1454,26 @@ alignedok:
     stosd;
     stosd;
     stosd;
-    // use ECX as a counter/4
-    push    ECX;
-    shr     ECX,2;
-    dec     ECX;
+    // use EDX as a counter/4
+    mov     EDX,ECX;
+    shr     EDX,2;
+    dec     EDX;
     // prepare XMM0
     movaps  XMM0,[EDI-16];
 storeloop:
     movaps  [EDI],XMM0;
     add     EDI,16;
-    dec     ECX;
+    dec     EDX;
     jnz     storeloop;
     //
-    pop     ECX;
     and     ECX,0x03;
     jz      done;
 simplestore:
     rep; stosd;
 done:
-    mov  EDI,EDX;
+    // restore EDI
+    mov  EDI,SS:[ESP+8];
+    ret  8;
   }
 }
 } else {
-- 
2.11.4.GIT