PPCRec: Fix stack pointer alignment for calls

cemu-project · Oct 30, 2024 · 8219a5f · 8219a5f
1 parent 83569ae
commit 8219a5f
Showing 1 changed file with 6 additions and 3 deletions.
diff --git a/src/Cafe/HW/Espresso/Recompiler/BackendX64/BackendX64.cpp b/src/Cafe/HW/Espresso/Recompiler/BackendX64/BackendX64.cpp
@@ -177,6 +177,7 @@ bool PPCRecompilerX64Gen_imlInstruction_macro(PPCRecFunction_t* PPCRecFunction,
 {
 	if (imlInstruction->operation == PPCREC_IML_MACRO_B_TO_REG)
 	{
+		//x64Gen_int3(x64GenContext);
 		uint32 branchDstReg = _reg32(imlInstruction->op_macro.paramReg);
 		if(X86_REG_RDX != branchDstReg)
 			x64Gen_mov_reg64_reg64(x64GenContext, X86_REG_RDX, branchDstReg);
@@ -553,10 +554,12 @@ void PPCRecompilerX64Gen_imlInstruction_atomic_cmp_store(PPCRecFunction_t* PPCRe
 void PPCRecompilerX64Gen_imlInstruction_call_imm(PPCRecFunction_t* PPCRecFunction, ppcImlGenContext_t* ppcImlGenContext, x64GenContext_t* x64GenContext, IMLInstruction* imlInstruction)
 {
 	// the register allocator takes care of spilling volatile registers and moving parameters to the right registers, so we don't need to do any special handling here
-	x64GenContext->emitter->SUB_qi8(X86_REG_RSP, 0x28); // reserve enough space for any parameters while keeping stack alignment of 16 intact
+	x64GenContext->emitter->SUB_qi8(X86_REG_RSP, 0x20); // reserve enough space for any parameters while keeping stack alignment of 16 intact
 	x64GenContext->emitter->MOV_qi64(X86_REG_RAX, imlInstruction->op_call_imm.callAddress);
 	x64GenContext->emitter->CALL_q(X86_REG_RAX);
-	x64GenContext->emitter->ADD_qi8(X86_REG_RSP, 0x28);
+	x64GenContext->emitter->ADD_qi8(X86_REG_RSP, 0x20);
+	// a note about the stack pointer:
+	// currently the code generated by generateEnterRecompilerCode makes sure the stack is 16 byte aligned, so we don't need to fix it up here
 }
 
 bool PPCRecompilerX64Gen_imlInstruction_r_r(PPCRecFunction_t* PPCRecFunction, ppcImlGenContext_t* ppcImlGenContext, x64GenContext_t* x64GenContext, IMLInstruction* imlInstruction)
@@ -1623,7 +1626,7 @@ void PPCRecompilerX64Gen_generateEnterRecompilerCode()
 {
 	x64GenContext_t x64GenContext{};
 
-	// start of recompiler entry function
+	// start of recompiler entry function (15 regs)
 	x64Gen_push_reg64(&x64GenContext, X86_REG_RAX);
 	x64Gen_push_reg64(&x64GenContext, X86_REG_RCX);
 	x64Gen_push_reg64(&x64GenContext, X86_REG_RDX);