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