Add more reasonable DAA pcode

Gekkio · Nov 21, 2022 · e7e8444 · e7e8444
1 parent 28147ad
commit e7e8444
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Showing 5 changed files with 23 additions and 8 deletions.
diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- DAA pseudo op tracks data dependencies much better
+
 ## 20221116 - 2022-11-16
 
 ### Changed

diff --git a/data/languages/sm83.sinc b/data/languages/sm83.sinc
@@ -121,7 +121,7 @@ HiMem8: (imm8) is imm8 {
 }
 
 define pcodeop IME;
-define pcodeop daa;
+define pcodeop daaOperand;
 define pcodeop halt;
 define pcodeop stop;
 

diff --git a/data/languages/sm83_instructions.sinc b/data/languages/sm83_instructions.sinc
@@ -457,7 +457,14 @@
 }
 
 :DAA is op0_8=0x27 {
-  A = daa(A);
+  local op8:1 = 0;
+  op8 = daaOperand(A, $(C_flag), $(H_flag), $(N_flag));
+  local tmp:1 = A + op8;
+  local co:1 = carry(A, op8);
+  $(Z_flag) = (tmp == 0);
+  $(H_flag) = 0;
+  $(C_flag) = $(C_flag) || ((!$(N_flag)) && co);
+  A = tmp;
 }
 
 :CPL is op0_8=0x2f {

diff --git a/src/test/kotlin/fi/gekkio/ghidraboy/decompiler/DecompilerTest.kt b/src/test/kotlin/fi/gekkio/ghidraboy/decompiler/DecompilerTest.kt
@@ -307,12 +307,14 @@ class DecompilerTest : IntegrationTest() {
             """
             byte daa(byte value)
             {
-                byte bVar1;
-                bVar1 = daa(value + 1);
-                if ((byte)(value + 1) == '\0') {
-                    return bVar1;
+                char cVar1;
+                byte bVar2;
+                cVar1 = daaOperand(value + 1,0xfe < value,((value & 0xf) + 1 & 0x10) != 0,0);
+                bVar2 = value + 1 + cVar1;
+                if (bVar2 == 0) {
+                    return bVar2;
                 }
-                return bVar1 + 1; 
+                return bVar2 + 1;
             }
             """.trimIndent()
         )

diff --git a/src/test/kotlin/fi/gekkio/ghidraboy/emu/MiscInstructionTest.kt b/src/test/kotlin/fi/gekkio/ghidraboy/emu/MiscInstructionTest.kt
@@ -66,7 +66,9 @@ class MiscInstructionTest : EmuTest() {
 
     @Test
     fun `DAA`() {
-        emulator.registerCallOtherCallback("daa", IgnorePCode())
+        emulator.registerCallOtherCallback("daaOperand", IgnorePCode())
+        emulator.writeF(0b0000_0000u)
+        emulator.writeA(0x00u)
         emulator.write(0x0000u, 0x27u)
         emulator.step()
         emulator.assertPC(0x0001u)