Changeset 89148 in vbox for trunk/include

Timestamp:

May 19, 2021 12:49:20 AM (4 years ago)

Author:

vboxsync

Message:

iprt/asm-watcom-x86-32.h: Fixed ASMBitLastSetU64. Was working like ASMBitFirstSetU64. bugref:10009

File:

• trunk/include/iprt/asm-watcom-x86-32.h (modified) (2 diffs)

trunk/include/iprt/asm-watcom-x86-32.h

@@ -656 +656 @@
 #ifdef IPRT_ASM_WATCOM_X86_32_WITH_PRAGMAS
 #pragma aux ASMBitLastSetU64 = \
-    "bsf eax, eax" \
-    "jz  not_found_low" \
-    "inc eax" \
-    "jmp done" \
-    \
-    "not_found_low:" \
-    "bsf eax, edx" \
+    "xchg eax, edx" \
+    "bsr eax, eax" \
     "jz  not_found_high" \
     "add eax, 33" \
@@ -668 +663 @@
     \
     "not_found_high:" \
+    "bsf eax, edx" \
+    "jz  not_found" \
+    "inc eax" \
+    "jmp done" \
+    \
+    "not_found:" \
     "xor eax, eax" \
     "done:" \
     parm [eax edx] nomemory \
     value [eax] \
-    modify exact [eax] nomemory;
+    modify exact [eax edx] nomemory;
 #endif