[CPU] Change thunk layout and fix Linux thunk misalignment

2 files changed, 101 insertions, 95 deletions

diff --git a/src/xenia/cpu/backend/x64/x64_backend.cc b/src/xenia/cpu/backend/x64/x64_backend.cc
index 8d3d48cee..60ee17dd6 100644
--- a/src/xenia/cpu/backend/x64/x64_backend.cc
+++ b/src/xenia/cpu/backend/x64/x64_backend.cc
@@ -580,11 +580,14 @@ void X64ThunkEmitter::EmitSaveVolatileRegs() {
   // mov(qword[rsp + offsetof(StackLayout::Thunk, r[0])], rax);
   mov(qword[rsp + offsetof(StackLayout::Thunk, r[1])], rcx);
   mov(qword[rsp + offsetof(StackLayout::Thunk, r[2])], rdx);
-  mov(qword[rsp + offsetof(StackLayout::Thunk, r[3])], r8);
-  mov(qword[rsp + offsetof(StackLayout::Thunk, r[4])], r9);
-  mov(qword[rsp + offsetof(StackLayout::Thunk, r[5])], r10);
-  mov(qword[rsp + offsetof(StackLayout::Thunk, r[6])], r11);
-
+#if XE_PLATFORM_LINUX
+  mov(qword[rsp + offsetof(StackLayout::Thunk, r[3])], rsi);
+  mov(qword[rsp + offsetof(StackLayout::Thunk, r[4])], rdi);
+#endif
+  mov(qword[rsp + offsetof(StackLayout::Thunk, r[5])], r8);
+  mov(qword[rsp + offsetof(StackLayout::Thunk, r[6])], r9);
+  mov(qword[rsp + offsetof(StackLayout::Thunk, r[7])], r10);
+  mov(qword[rsp + offsetof(StackLayout::Thunk, r[8])], r11);
   // vmovaps(qword[rsp + offsetof(StackLayout::Thunk, xmm[0])], xmm0);
   vmovaps(qword[rsp + offsetof(StackLayout::Thunk, xmm[1])], xmm1);
   vmovaps(qword[rsp + offsetof(StackLayout::Thunk, xmm[2])], xmm2);
@@ -594,35 +597,40 @@ void X64ThunkEmitter::EmitSaveVolatileRegs() {
 }
 
 void X64ThunkEmitter::EmitLoadVolatileRegs() {
-  // Load volatile registers from our stack frame.
+  // mov(rax, qword[rsp + offsetof(StackLayout::Thunk, r[0])]);
+  mov(rcx, qword[rsp + offsetof(StackLayout::Thunk, r[1])]);
+  mov(rdx, qword[rsp + offsetof(StackLayout::Thunk, r[2])]);
+#if XE_PLATFORM_LINUX
+  mov(rsi, qword[rsp + offsetof(StackLayout::Thunk, r[3])]);
+  mov(rdi, qword[rsp + offsetof(StackLayout::Thunk, r[4])]);
+#endif
+  mov(r8, qword[rsp + offsetof(StackLayout::Thunk, r[5])]);
+  mov(r9, qword[rsp + offsetof(StackLayout::Thunk, r[6])]);
+  mov(r10, qword[rsp + offsetof(StackLayout::Thunk, r[7])]);
+  mov(r11, qword[rsp + offsetof(StackLayout::Thunk, r[8])]);
   // vmovaps(xmm0, qword[rsp + offsetof(StackLayout::Thunk, xmm[0])]);
   vmovaps(xmm1, qword[rsp + offsetof(StackLayout::Thunk, xmm[1])]);
   vmovaps(xmm2, qword[rsp + offsetof(StackLayout::Thunk, xmm[2])]);
   vmovaps(xmm3, qword[rsp + offsetof(StackLayout::Thunk, xmm[3])]);
   vmovaps(xmm4, qword[rsp + offsetof(StackLayout::Thunk, xmm[4])]);
   vmovaps(xmm5, qword[rsp + offsetof(StackLayout::Thunk, xmm[5])]);
-
-  // mov(rax, qword[rsp + offsetof(StackLayout::Thunk, r[0])]);
-  mov(rcx, qword[rsp + offsetof(StackLayout::Thunk, r[1])]);
-  mov(rdx, qword[rsp + offsetof(StackLayout::Thunk, r[2])]);
-  mov(r8, qword[rsp + offsetof(StackLayout::Thunk, r[3])]);
-  mov(r9, qword[rsp + offsetof(StackLayout::Thunk, r[4])]);
-  mov(r10, qword[rsp + offsetof(StackLayout::Thunk, r[5])]);
-  mov(r11, qword[rsp + offsetof(StackLayout::Thunk, r[6])]);
 }
 
 void X64ThunkEmitter::EmitSaveNonvolatileRegs() {
-  // Preserve nonvolatile registers.
   mov(qword[rsp + offsetof(StackLayout::Thunk, r[0])], rbx);
-  mov(qword[rsp + offsetof(StackLayout::Thunk, r[1])], rcx);
-  mov(qword[rsp + offsetof(StackLayout::Thunk, r[2])], rbp);
+  mov(qword[rsp + offsetof(StackLayout::Thunk, r[1])], rbp);
+#if XE_PLATFORM_WIN32
+  mov(qword[rsp + offsetof(StackLayout::Thunk, r[2])], rcx);
   mov(qword[rsp + offsetof(StackLayout::Thunk, r[3])], rsi);
   mov(qword[rsp + offsetof(StackLayout::Thunk, r[4])], rdi);
+#endif
   mov(qword[rsp + offsetof(StackLayout::Thunk, r[5])], r12);
   mov(qword[rsp + offsetof(StackLayout::Thunk, r[6])], r13);
   mov(qword[rsp + offsetof(StackLayout::Thunk, r[7])], r14);
   mov(qword[rsp + offsetof(StackLayout::Thunk, r[8])], r15);
 
+  // SysV does not have nonvolatile XMM registers.
+#if XE_PLATFORM_WIN32
   vmovaps(qword[rsp + offsetof(StackLayout::Thunk, xmm[0])], xmm6);
   vmovaps(qword[rsp + offsetof(StackLayout::Thunk, xmm[1])], xmm7);
   vmovaps(qword[rsp + offsetof(StackLayout::Thunk, xmm[2])], xmm8);
@@ -633,9 +641,23 @@ void X64ThunkEmitter::EmitSaveNonvolatileRegs() {
   vmovaps(qword[rsp + offsetof(StackLayout::Thunk, xmm[7])], xmm13);
   vmovaps(qword[rsp + offsetof(StackLayout::Thunk, xmm[8])], xmm14);
   vmovaps(qword[rsp + offsetof(StackLayout::Thunk, xmm[9])], xmm15);
+#endif
 }
 
 void X64ThunkEmitter::EmitLoadNonvolatileRegs() {
+  mov(rbx, qword[rsp + offsetof(StackLayout::Thunk, r[0])]);
+  mov(rbp, qword[rsp + offsetof(StackLayout::Thunk, r[1])]);
+#if XE_PLATFORM_WIN32
+  mov(rcx, qword[rsp + offsetof(StackLayout::Thunk, r[2])]);
+  mov(rsi, qword[rsp + offsetof(StackLayout::Thunk, r[3])]);
+  mov(rdi, qword[rsp + offsetof(StackLayout::Thunk, r[4])]);
+#endif
+  mov(r12, qword[rsp + offsetof(StackLayout::Thunk, r[5])]);
+  mov(r13, qword[rsp + offsetof(StackLayout::Thunk, r[6])]);
+  mov(r14, qword[rsp + offsetof(StackLayout::Thunk, r[7])]);
+  mov(r15, qword[rsp + offsetof(StackLayout::Thunk, r[8])]);
+
+#if XE_PLATFORM_WIN32
   vmovaps(xmm6, qword[rsp + offsetof(StackLayout::Thunk, xmm[0])]);
   vmovaps(xmm7, qword[rsp + offsetof(StackLayout::Thunk, xmm[1])]);
   vmovaps(xmm8, qword[rsp + offsetof(StackLayout::Thunk, xmm[2])]);
@@ -646,16 +668,7 @@ void X64ThunkEmitter::EmitLoadNonvolatileRegs() {
   vmovaps(xmm13, qword[rsp + offsetof(StackLayout::Thunk, xmm[7])]);
   vmovaps(xmm14, qword[rsp + offsetof(StackLayout::Thunk, xmm[8])]);
   vmovaps(xmm15, qword[rsp + offsetof(StackLayout::Thunk, xmm[9])]);
-
-  mov(rbx, qword[rsp + offsetof(StackLayout::Thunk, r[0])]);
-  mov(rcx, qword[rsp + offsetof(StackLayout::Thunk, r[1])]);
-  mov(rbp, qword[rsp + offsetof(StackLayout::Thunk, r[2])]);
-  mov(rsi, qword[rsp + offsetof(StackLayout::Thunk, r[3])]);
-  mov(rdi, qword[rsp + offsetof(StackLayout::Thunk, r[4])]);
-  mov(r12, qword[rsp + offsetof(StackLayout::Thunk, r[5])]);
-  mov(r13, qword[rsp + offsetof(StackLayout::Thunk, r[6])]);
-  mov(r14, qword[rsp + offsetof(StackLayout::Thunk, r[7])]);
-  mov(r15, qword[rsp + offsetof(StackLayout::Thunk, r[8])]);
+#endif
 }
 
 }  // namespace x64
diff --git a/src/xenia/cpu/backend/x64/x64_stack_layout.h b/src/xenia/cpu/backend/x64/x64_stack_layout.h
index 3835bb82e..1736dc02a 100644
--- a/src/xenia/cpu/backend/x64/x64_stack_layout.h
+++ b/src/xenia/cpu/backend/x64/x64_stack_layout.h
@@ -27,78 +27,71 @@ class StackLayout {
    * NOTE: stack must always be 16b aligned.
    *
    * Thunk stack:
-   *  +------------------+
-   *  | arg temp, 3 * 8  | rsp + 0
-   *  |                  |
-   *  |                  |
-   *  +------------------+
-   *  | scratch, 16b     | rsp + 24
-   *  |                  |
-   *  +------------------+
-   *  | rbx              | rsp + 40
-   *  +------------------+
-   *  | rcx / context    | rsp + 48
-   *  +------------------+
-   *  | rbp              | rsp + 56
-   *  +------------------+
-   *  | rsi              | rsp + 64
-   *  +------------------+
-   *  | rdi              | rsp + 72
-   *  +------------------+
-   *  | r12              | rsp + 80
-   *  +------------------+
-   *  | r13              | rsp + 88
-   *  +------------------+
-   *  | r14              | rsp + 96
-   *  +------------------+
-   *  | r15              | rsp + 104
-   *  +------------------+
-   *  | xmm6/0           | rsp + 112
-   *  |                  |
-   *  +------------------+
-   *  | xmm7/1           | rsp + 128
-   *  |                  |
-   *  +------------------+
-   *  | xmm8/2           | rsp + 144
-   *  |                  |
-   *  +------------------+
-   *  | xmm9/3           | rsp + 160
-   *  |                  |
-   *  +------------------+
-   *  | xmm10/4          | rsp + 176
-   *  |                  |
-   *  +------------------+
-   *  | xmm11/5          | rsp + 192
-   *  |                  |
-   *  +------------------+
-   *  | xmm12            | rsp + 208
-   *  |                  |
-   *  +------------------+
-   *  | xmm13            | rsp + 224
-   *  |                  |
-   *  +------------------+
-   *  | xmm14            | rsp + 240
-   *  |                  |
-   *  +------------------+
-   *  | xmm15            | rsp + 256
-   *  |                  |
-   *  +------------------+
-   *  | scratch, 8b      | rsp + 272
-   *  |                  |
-   *  +------------------+
-   *  | (return address) | rsp + 280
-   *  +------------------+
-   *  | (rcx home)       | rsp + 288
-   *  +------------------+
-   *  | (rdx home)       | rsp + 296
-   *  +------------------+
+   *      Non-Volatile         Volatile
+   *  +------------------+------------------+
+   *  | arg temp, 3 * 8  | arg temp, 3 * 8  | rsp + 0x000
+   *  |                  |                  |
+   *  |                  |                  |
+   *  +------------------+------------------+
+   *  | rbx              | (unused)         | rsp + 0x018
+   *  +------------------+------------------+
+   *  | rbp              | rcx              | rsp + 0x020
+   *  +------------------+------------------+
+   *  | rcx (Win32)      | rdx              | rsp + 0x028
+   *  +------------------+------------------+
+   *  | rsi (Win32)      | rsi (Linux)      | rsp + 0x030
+   *  +------------------+------------------+
+   *  | rdi (Win32)      | rdi (Linux)      | rsp + 0x038
+   *  +------------------+------------------+
+   *  | r12              | r8               | rsp + 0x040
+   *  +------------------+------------------+
+   *  | r13              | r9               | rsp + 0x048
+   *  +------------------+------------------+
+   *  | r14              | r10              | rsp + 0x050
+   *  +------------------+------------------+
+   *  | r15              | r11              | rsp + 0x058
+   *  +------------------+------------------+
+   *  | xmm6 (Win32)     | (unused)         | rsp + 0x060
+   *  |                  |                  |
+   *  +------------------+------------------+
+   *  | xmm7 (Win32)     | xmm1             | rsp + 0x070
+   *  |                  |                  |
+   *  +------------------+------------------+
+   *  | xmm8 (Win32)     | xmm2             | rsp + 0x080
+   *  |                  |                  |
+   *  +------------------+------------------+
+   *  | xmm9 (Win32)     | xmm3             | rsp + 0x090
+   *  |                  |                  |
+   *  +------------------+------------------+
+   *  | xmm10 (Win32)    | xmm4             | rsp + 0x0A0
+   *  |                  |                  |
+   *  +------------------+------------------+
+   *  | xmm11 (Win32)    | xmm5             | rsp + 0x0B0
+   *  |                  |                  |
+   *  +------------------+------------------+
+   *  | xmm12 (Win32)    | (unused)         | rsp + 0x0C0
+   *  |                  |                  |
+   *  +------------------+------------------+
+   *  | xmm13 (Win32)    | (unused)         | rsp + 0x0D0
+   *  |                  |                  |
+   *  +------------------+------------------+
+   *  | xmm14 (Win32)    | (unused)         | rsp + 0x0E0
+   *  |                  |                  |
+   *  +------------------+------------------+
+   *  | xmm15 (Win32)    | (unused)         | rsp + 0x0F0
+   *  |                  |                  |
+   *  +------------------+------------------+
+   *  | (return address) | (return address) | rsp + 0x100
+   *  +------------------+------------------+
+   *  | (rcx home)       | (rcx home)       | rsp + 0x108
+   *  +------------------+------------------+
+   *  | (rdx home)       | (rdx home)       | rsp + 0x110
+   *  +------------------+------------------+
    */
   XEPACKEDSTRUCT(Thunk, {
     uint64_t arg_temp[3];
-    uint8_t scratch[16];
-    uint64_t r[10];
+    uint64_t r[9];
     vec128_t xmm[10];
-    uint64_t dummy;
   });
   static_assert(sizeof(Thunk) % 16 == 0,
                 "sizeof(Thunk) must be a multiple of 16!");