57 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			57 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			LLVM
		
	
	
	
; RUN: llc -mtriple=x86_64-apple-darwin -o - %s | FileCheck %s
 | 
						|
 | 
						|
; Simple case: completely identical returns, even with extensions, shouldn't be
 | 
						|
; a barrier to tail calls.
 | 
						|
declare zeroext i1 @give_bool()
 | 
						|
define zeroext i1 @test_bool() {
 | 
						|
; CHECK-LABEL: test_bool:
 | 
						|
; CHECK: jmp
 | 
						|
  %call = tail call zeroext i1 @give_bool()
 | 
						|
  ret i1 %call
 | 
						|
}
 | 
						|
 | 
						|
; Here, there's more zero extension to be done between the call and the return,
 | 
						|
; so a tail call is impossible (well, according to current Clang practice
 | 
						|
; anyway. The AMD64 ABI isn't crystal clear on the matter).
 | 
						|
; FIXME: The high 24 bits returned from test_i32 are undefined; do tail call!
 | 
						|
declare zeroext i32 @give_i32()
 | 
						|
define zeroext i8 @test_i32() {
 | 
						|
; CHECK-LABEL: test_i32:
 | 
						|
; CHECK: callq _give_i32
 | 
						|
; CHECK: ret
 | 
						|
 | 
						|
  %call = tail call zeroext i32 @give_i32()
 | 
						|
  %val = trunc i32 %call to i8
 | 
						|
  ret i8 %val
 | 
						|
}
 | 
						|
 | 
						|
; Here, one function is zeroext and the other is signext. To the extent that
 | 
						|
; these both mean something they are incompatible so no tail call is possible.
 | 
						|
; FIXME: The high 16 bits returned are undefined; do tail call!
 | 
						|
declare zeroext i16 @give_unsigned_i16()
 | 
						|
define signext i16 @test_incompatible_i16() {
 | 
						|
; CHECK-LABEL: test_incompatible_i16:
 | 
						|
; CHECK: callq _give_unsigned_i16
 | 
						|
; CHECK: ret
 | 
						|
 | 
						|
  %call = tail call zeroext i16 @give_unsigned_i16()
 | 
						|
  ret i16 %call
 | 
						|
}
 | 
						|
 | 
						|
declare inreg i32 @give_i32_inreg()
 | 
						|
define i32 @test_inreg_to_normal() {
 | 
						|
; CHECK-LABEL: test_inreg_to_normal:
 | 
						|
; CHECK: callq _give_i32_inreg
 | 
						|
; CHECK: ret
 | 
						|
  %val = tail call inreg i32 @give_i32_inreg()
 | 
						|
  ret i32 %val
 | 
						|
}
 | 
						|
 | 
						|
define inreg i32 @test_normal_to_inreg() {
 | 
						|
; CHECK-LABEL: test_normal_to_inreg:
 | 
						|
; CHECK: callq _give_i32
 | 
						|
; CHECK: ret
 | 
						|
  %val = tail call i32 @give_i32()
 | 
						|
  ret i32 %val
 | 
						|
}
 |