[reactos] 02/07: [RTL] Improve / fix the SList code

[Timo Kreuzer]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=65c3911ffcf74a051c9366...

commit 65c3911ffcf74a051c9366892230380a81ad82bd
Author:     Timo Kreuzer [e-mail]
AuthorDate: Wed Mar 7 12:03:51 2018 +0100
Commit:     Timo Kreuzer [e-mail]
CommitDate: Sat Jun 5 13:52:42 2021 +0200

[RTL] Improve / fix the SList code

Don't push a register in the middle of a an asm function. Instead add a proper prolog and store rbx in a home param slot.
---
 sdk/lib/rtl/amd64/slist.S | 68 +++++++++++++++++++++++++++++------------------
 1 file changed, 42 insertions(+), 26 deletions(-)

diff --git a/sdk/lib/rtl/amd64/slist.S b/sdk/lib/rtl/amd64/slist.S
index 08eb382351d..a29ecd6a169 100644
--- a/sdk/lib/rtl/amd64/slist.S
+++ b/sdk/lib/rtl/amd64/slist.S
@@ -83,17 +83,18 @@ PUBLIC ExpInterlockedPopEntrySListEnd16
 PUBLIC ExpInterlockedPushEntrySList
 PUBLIC ExpInterlockedFlushSList

-PUBLIC RtlInterlockedFlushSList
 PUBLIC RtlInterlockedPopEntrySList
 PUBLIC RtlInterlockedPushEntrySList
+PUBLIC RtlInterlockedFlushSList

/* PSLIST_ENTRY
  * NTAPI
  * RtlInterlockedPopEntrySList(
  *     IN PSLIST_HEADER ListHead);
  */
-RtlInterlockedPopEntrySList:
 ExpInterlockedPopEntrySList:
+FUNC RtlInterlockedPopEntrySList
+    .ENDPROLOG

/* Load ListHead->Region into rdx */
     mov rdx, [rcx + 8]
@@ -106,8 +107,7 @@ ExpInterlockedPopEntrySList:
     jne RtlInterlockedPopEntrySList16

/* Use the 8 byte header */
-
-ExpInterlockedPopEntrySListResume:
+GLOBAL_LABEL ExpInterlockedPopEntrySListResume

/* Check if ListHead->NextEntry is NULL */
     mov r9, rax
@@ -128,7 +128,7 @@ ExpInterlockedPopEntrySListResume:
     /* Combine to new pointer in rdx */
     or rdx, r9

-ExpInterlockedPopEntrySListFault:
+GLOBAL_LABEL ExpInterlockedPopEntrySListFault

/* Load the next NextEntry pointer to r9 */
     mov r9, [rdx]
@@ -139,7 +139,7 @@ ExpInterlockedPopEntrySListFault:
     /* Combine into r8 */
     or r8, r9

-ExpInterlockedPopEntrySListEnd:
+GLOBAL_LABEL ExpInterlockedPopEntrySListEnd

/* If [rcx] equals rax, exchange it with r8 */
     lock cmpxchg [rcx], r8
@@ -160,29 +160,34 @@ ExpInterlockedPopEntrySListEnd:
     ret

RtlInterlockedPopEntrySListEmpty:
+
     xor rax, rax
     ret

-RtlInterlockedPopEntrySList16:
+ENDFUNC
+
+
+FUNC RtlInterlockedPopEntrySList16
+    mov [rsp + P3Home], rbx
+    .SAVEREG rbx, P3Home
+    .ENDPROLOG
+
     /* This is a 16 byte header
        rcx == ListHead
        rdx == ListHead->Region
        rax == ListHead->Alignment */

-    /* Save rbx */
-    push rbx
-
     /* Copy rcx to r8, as we need rcx for the exchange */
     mov r8, rcx

-ExpInterlockedPopEntrySListResume16:
+GLOBAL_LABEL ExpInterlockedPopEntrySListResume16

/* Set r9 = ListHead->NextEntry and check if it is NULL */
     mov r9, rdx
     and r9, SLIST16B_NEXTENTRY_MASK
     jz RtlInterlockedPopEntrySListEmpty16

-ExpInterlockedPopEntrySListFault16:
+GLOBAL_LABEL ExpInterlockedPopEntrySListFault16

/* Set NewListHead.Next = ListHead->NextEntry->Next */
     mov rcx, [r9]
@@ -193,7 +198,7 @@ ExpInterlockedPopEntrySListFault16:
     /* Copy Depth and Sequence number and adjust Depth */
     lea rbx, [rax - SLIST16A_DEPTH_INC]

-ExpInterlockedPopEntrySListEnd16:
+GLOBAL_LABEL ExpInterlockedPopEntrySListEnd16

/* If [r8] equals rdx:rax, exchange it with rcx:rbx */
     lock cmpxchg16b [r8]
@@ -206,13 +211,15 @@ ExpInterlockedPopEntrySListEnd16:
     and rax, SLIST16B_NEXTENTRY_MASK

/* Return */
-    pop rbx
+    mov rbx, [rsp + P3Home]
     ret

RtlInterlockedPopEntrySListEmpty16:
+
     xor rax, rax
-    pop rbx
+    mov rbx, [rsp + P3Home]
     ret
+ENDFUNC

/* PSLIST_ENTRY
@@ -221,8 +228,9 @@ RtlInterlockedPopEntrySListEmpty16:
  *     IN PSLIST_HEADER ListHead,
  *     IN PSLIST_ENTRY ListEntry);
  */
-RtlInterlockedPushEntrySList:
 ExpInterlockedPushEntrySList:
+FUNC RtlInterlockedPushEntrySList
+    .ENDPROLOG

#if DBG
     /* Make sure the ListEntry is 16 bytes aligned */
@@ -298,16 +306,19 @@ RtlInterlockedPushEntrySListEmpty:
     mov rax, r9
     ret

-RtlInterlockedPushEntrySList16:
+ENDFUNC
+
+FUNC RtlInterlockedPushEntrySList16
+    mov [rsp + P3Home], rbx
+    .SAVEREG rbx, P3Home
+    .ENDPROLOG
+
     /* This is a 16 byte header
        rcx = ListHead
        rdx = ListEntry
        rax = ListHead->Alignment
        r9 = ListHead->Region */

-    /* Save rbx */
-    push rbx
-
     /* Copy rcx/rdx to r8/r9, as we need rcx/rdx for the exchange */
     mov r8, rcx
     mov r9, rdx
@@ -349,17 +360,23 @@ RtlInterlockedPushEntrySListLoop16:
     and rax, SLIST16B_NEXTENTRY_MASK

/* Return */
-    pop rbx
+    mov rbx, [rsp + P3Home]
     ret

+ENDFUNC
+

/* PSLIST_ENTRY
  * NTAPI
  * RtlInterlockedFlushSList(
  *     IN PSLIST_HEADER ListHead);
  */
-RtlInterlockedFlushSList:
 ExpInterlockedFlushSList:
+FUNC RtlInterlockedFlushSList
+    
+    mov [rsp + P3Home], rbx
+    .SAVEREG rbx, P3Home
+    .ENDPROLOG

/* Load ListHead->Region into rdx */
     mov rdx, [rcx + 8]
@@ -403,9 +420,6 @@ RtlInterlockedFlushSList16:
         rdx = ListHead->Region
     */

-    /* Save rbx */
-    push rbx
-
     /* Load ListHead into r8, as we need rcx for the exchange */
     mov r8, rcx

@@ -426,8 +440,10 @@ RtlInterlockedFlushSListLoop16:
     and rax, SLIST16B_NEXTENTRY_MASK

/* Return */
-    pop rbx
+    mov rbx, [rsp + P3Home]
     ret

+ENDFUNC
+
 END