Preserve uext and sext flags for parameters on x86_64 and apple aarch64

This is required by the ABI and prevents a miscompilation when calling
LLVM compiled functions.

cranelift/codegen/src/isa/aarch64/abi.rs

@@ -1148,10 +1148,14 @@ impl ABIMachineSpec for AArch64MachineDeps {
     }
 
     fn get_ext_mode(
-        _call_conv: isa::CallConv,
-        _specified: ir::ArgumentExtension,
+        call_conv: isa::CallConv,
+        specified: ir::ArgumentExtension,
     ) -> ir::ArgumentExtension {
-        ir::ArgumentExtension::None
+        if call_conv == isa::CallConv::AppleAarch64 {
+            specified
+        } else {
+            ir::ArgumentExtension::None
+        }
     }
 
     fn compute_frame_layout(

cranelift/codegen/src/isa/x64/abi.rs

@@ -809,9 +809,9 @@ impl ABIMachineSpec for X64ABIMachineSpec {
 
     fn get_ext_mode(
         _call_conv: isa::CallConv,
-        _specified: ir::ArgumentExtension,
+        specified: ir::ArgumentExtension,
     ) -> ir::ArgumentExtension {
-        ir::ArgumentExtension::None
+        specified
     }
 
     fn compute_frame_layout(

cranelift/filetests/filetests/isa/aarch64/uext-sext-handling.clif

@@ -0,0 +1,69 @@
+test compile precise-output
+target aarch64
+
+function u0:0(i8) system_v {
+    ; The aapcs64 call conv ignores the uext and sext flags
+    sig0 = (i8 uext) system_v
+    fn0 = u0:0 sig0
+
+block0(v0: i8):
+    call fn0(v0)
+    return
+}
+
+; VCode:
+;   stp fp, lr, [sp, #-16]!
+;   mov fp, sp
+; block0:
+;   load_ext_name x2, User(userextname0)+0
+;   blr x2
+;   ldp fp, lr, [sp], #16
+;   ret
+;
+; Disassembled:
+; block0: ; offset 0x0
+;   stp x29, x30, [sp, #-0x10]!
+;   mov x29, sp
+; block1: ; offset 0x8
+;   ldr x2, #0x10
+;   b #0x18
+;   .byte 0x00, 0x00, 0x00, 0x00 ; reloc_external Abs8 u0:0 0
+;   .byte 0x00, 0x00, 0x00, 0x00
+;   blr x2
+;   ldp x29, x30, [sp], #0x10
+;   ret
+
+function u0:0(i8) apple_aarch64 {
+    ; The aaple aarch64 call conv respects the uext and sext flags
+    sig0 = (i8 uext) apple_aarch64
+    fn0 = u0:0 sig0
+
+block0(v0: i8):
+    call fn0(v0)
+    return
+}
+
+; VCode:
+;   stp fp, lr, [sp, #-16]!
+;   mov fp, sp
+; block0:
+;   uxtb w0, w0
+;   load_ext_name x4, User(userextname0)+0
+;   blr x4
+;   ldp fp, lr, [sp], #16
+;   ret
+;
+; Disassembled:
+; block0: ; offset 0x0
+;   stp x29, x30, [sp, #-0x10]!
+;   mov x29, sp
+; block1: ; offset 0x8
+;   uxtb w0, w0
+;   ldr x4, #0x14
+;   b #0x1c
+;   .byte 0x00, 0x00, 0x00, 0x00 ; reloc_external Abs8 u0:0 0
+;   .byte 0x00, 0x00, 0x00, 0x00
+;   blr x4
+;   ldp x29, x30, [sp], #0x10
+;   ret
+

cranelift/filetests/filetests/isa/x64/uext-sext-handling.clif

@@ -0,0 +1,75 @@
+test compile precise-output
+target x86_64
+
+function u0:0(i8) system_v {
+    ; The x86_64 system_v call conv respects uext and sext
+    sig0 = (i8 uext) system_v
+    fn0 = u0:0 sig0
+
+block0(v0: i8):
+    call fn0(v0)
+    return
+}
+
+; VCode:
+;   pushq   %rbp
+;   movq    %rsp, %rbp
+; block0:
+;   movzbq  %dil, %rdi
+;   load_ext_name userextname0+0, %rdx
+;   call    *%rdx
+;   movq    %rbp, %rsp
+;   popq    %rbp
+;   ret
+;
+; Disassembled:
+; block0: ; offset 0x0
+;   pushq %rbp
+;   movq %rsp, %rbp
+; block1: ; offset 0x4
+;   movzbq %dil, %rdi
+;   movabsq $0, %rdx ; reloc_external Abs8 u0:0 0
+;   callq *%rdx
+;   movq %rbp, %rsp
+;   popq %rbp
+;   retq
+
+function u0:0(i8) windows_fastcall {
+    ; The x86_64 windows_fastcall call conv respects uext and sext
+    sig0 = (i8 uext) windows_fastcall
+    fn0 = u0:0 sig0
+
+block0(v0: i8):
+    call fn0(v0)
+    return
+}
+
+; VCode:
+;   pushq   %rbp
+;   movq    %rsp, %rbp
+; block0:
+;   subq    %rsp, $32, %rsp
+;   virtual_sp_offset_adjust 32
+;   movzbq  %cl, %rcx
+;   load_ext_name userextname0+0, %r9
+;   call    *%r9
+;   addq    %rsp, $32, %rsp
+;   virtual_sp_offset_adjust -32
+;   movq    %rbp, %rsp
+;   popq    %rbp
+;   ret
+;
+; Disassembled:
+; block0: ; offset 0x0
+;   pushq %rbp
+;   movq %rsp, %rbp
+; block1: ; offset 0x4
+;   subq $0x20, %rsp
+;   movzbq %cl, %rcx
+;   movabsq $0, %r9 ; reloc_external Abs8 u0:0 0
+;   callq *%r9
+;   addq $0x20, %rsp
+;   movq %rbp, %rsp
+;   popq %rbp
+;   retq
+