Add clang inline asm leaf attribute and clobbers

MEGA65 · Sep 1, 2024 · acdedad · acdedad
1 parent eac0745
commit acdedad
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Showing 3 changed files with 46 additions and 37 deletions.
diff --git a/src/debug.c b/src/debug.c
@@ -14,11 +14,11 @@ void debug_msg(char* msg)
         __asm__("STA $D643");
         __asm__("CLV");
 #else
-        asm volatile("st%0 $d643\n"
-                     "clv\n"
-                     :           /* no output operands */
-                     : "a"(*msg) /* input operands */
-                     : /* clobber list */);
+        __attribute__((leaf)) asm volatile("st%0 $d643\n"
+                                           "clv\n"
+                                           :           /* no output operands */
+                                           : "a"(*msg) /* input operands */
+                                           : "p" /* clobber list */);
 #endif
         msg++;
     }
@@ -31,15 +31,15 @@ void debug_msg(char* msg)
     __asm__("CLV");
 #else
     // clearing Z seems to fix occasional xemu freeze. Why?
-    asm volatile("lda #$0d\n"
-                 "sta $d643\n"
-                 "clv\n"
-                 "lda #$0a\n"
-                 "sta $d643\n"
-                 "clv\n"
-                 "ldz #0\n"
-                 : /* no output operands */
-                 : /* no input operands*/
-                 : "a" /* clobber list */);
+    __attribute__((leaf)) asm volatile("lda #$0d  \n"
+                                       "sta $d643 \n"
+                                       "clv       \n"
+                                       "lda #$0a  \n"
+                                       "sta $d643 \n"
+                                       "clv       \n"
+                                       "ldz #0    \n"
+                                       : /* no output operands */
+                                       : /* no input operands*/
+                                       : "a", "p" /* clobber list */);
 #endif
 }
diff --git a/src/fcio.c b/src/fcio.c
@@ -206,13 +206,15 @@ unsigned char fc_nyblswap(unsigned char in) // oh why?!
     __asm__("sta %v", swp);
     return swp;
 #elif defined(__clang__)
-    asm volatile("asl a\n"
-                 "adc #$80\n"
-                 "rol a\n"
-                 "asl a\n"
-                 "adc #$80\n"
-                 "rol a\n"
-                 : "+a"(in));
+    __attribute__((leaf)) asm volatile("asl a    \n"
+                                       "adc #$80 \n"
+                                       "rol a    \n"
+                                       "asl a    \n"
+                                       "adc #$80 \n"
+                                       "rol a    \n"
+                                       : "+a"(in) /* output */
+                                       :          /* no input */
+                                       : "p" /* clobbers */);
     return in;
 #else
 #pragma GCC warning "fc_nyblswap() is not implemented for this compiler"

diff --git a/src/tests.c b/src/tests.c
@@ -62,14 +62,20 @@ void unit_test_report(
     __asm__("STA $D643");
     __asm__("CLV");
 #else
-    asm volatile("st%0 $D643\n"
-                 "clv" ::"a"((uint8_t)(issue & 0xff)));
-    asm volatile("st%0 $D643\n"
-                 "clv" ::"a"((uint8_t)(issue >> 8)));
-    asm volatile("st%0 $D643\n"
-                 "clv" ::"a"(sub));
-    asm volatile("st%0 $D643\n"
-                 "clv" ::"a"(status));
+    __attribute__((leaf)) asm volatile(
+        "st%0 $D643 \n"
+        "clv        \n" ::"a"((uint8_t)(issue & 0xff))
+        : "p");
+    __attribute__((leaf)) asm volatile(
+        "st%0 $D643 \n"
+        "clv        \n" ::"a"((uint8_t)(issue >> 8))
+        : "p");
+    __attribute__((leaf)) asm volatile("st%0 $D643 \n"
+                                       "clv        \n" ::"a"(sub)
+                                       : "p");
+    __attribute__((leaf)) asm volatile("st%0 $D643 \n"
+                                       "clv        \n" ::"a"(status)
+                                       : "p");
 #endif
 }
 
@@ -78,7 +84,7 @@ void _unit_test_msg(char* msg, char cmd)
     unsigned char* current;
 
     unit_test_report(0, 0, cmd);
-    current = (unsigned char *)msg;
+    current = (unsigned char*)msg;
 
     while (*current) {
 #ifdef __CC65__
@@ -87,8 +93,9 @@ void _unit_test_msg(char* msg, char cmd)
         __asm__("STA $D643");
         __asm__("CLV");
 #else
-        asm volatile("st%0 $D643\n"
-                     "clv" ::"a"(*current));
+        __attribute__((leaf)) asm volatile("st%0 $D643 \n"
+                                           "clv        \n" ::"a"(*current)
+                                           : "p");
 #endif
         current++;
     }
@@ -98,10 +105,10 @@ void _unit_test_msg(char* msg, char cmd)
     __asm__("STA $D643");
     __asm__("CLV");
 #else
-    asm volatile("lda #92\n"
-                 "sta $D643\n"
-                 "clv" ::
-                     : "a");
+    __attribute__((leaf)) asm volatile("lda #92   \n"
+                                       "sta $D643 \n"
+                                       "clv       \n" ::
+                                           : "a", "p");
 #endif
 }