123 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			123 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			LLVM
		
	
	
	
; RUN: opt -S -instcombine < %s | FileCheck %s
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; <rdar://problem/8558713>
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declare void @throwAnExceptionOrWhatever()
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; CHECK-LABEL: @test1(
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define i32 @test1(i32 %a, i32 %b) nounwind ssp {
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entry:
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; CHECK-NOT: sext
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  %conv = sext i32 %a to i64
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  %conv2 = sext i32 %b to i64
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  %add = add nsw i64 %conv2, %conv
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  %add.off = add i64 %add, 2147483648
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; CHECK: llvm.sadd.with.overflow.i32
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  %0 = icmp ugt i64 %add.off, 4294967295
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  br i1 %0, label %if.then, label %if.end
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if.then:
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  tail call void @throwAnExceptionOrWhatever() nounwind
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  br label %if.end
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if.end:
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; CHECK-NOT: trunc
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  %conv9 = trunc i64 %add to i32
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; CHECK: ret i32
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  ret i32 %conv9
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}
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; CHECK-LABEL: @test2(
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; This form should not be promoted for two reasons: 1) it is unprofitable to
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; promote it since the add.off instruction has another use, and 2) it is unsafe
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; because the add-with-off makes the high bits of the original add live.
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define i32 @test2(i32 %a, i32 %b, i64* %P) nounwind ssp {
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entry:
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  %conv = sext i32 %a to i64
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  %conv2 = sext i32 %b to i64
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  %add = add nsw i64 %conv2, %conv
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  %add.off = add i64 %add, 2147483648
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  store i64 %add.off, i64* %P
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; CHECK-NOT: llvm.sadd.with.overflow
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  %0 = icmp ugt i64 %add.off, 4294967295
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  br i1 %0, label %if.then, label %if.end
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if.then:
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  tail call void @throwAnExceptionOrWhatever() nounwind
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  br label %if.end
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if.end:
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  %conv9 = trunc i64 %add to i32
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; CHECK: ret i32
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  ret i32 %conv9
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}
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; CHECK: test3
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; PR8816
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; This is illegal to transform because the high bits of the original add are
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; live out.
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define i64 @test3(i32 %a, i32 %b) nounwind ssp {
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entry:
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  %conv = sext i32 %a to i64
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  %conv2 = sext i32 %b to i64
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  %add = add nsw i64 %conv2, %conv
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  %add.off = add i64 %add, 2147483648
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; CHECK-NOT: llvm.sadd.with.overflow
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  %0 = icmp ugt i64 %add.off, 4294967295
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  br i1 %0, label %if.then, label %if.end
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if.then:
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  tail call void @throwAnExceptionOrWhatever() nounwind
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  br label %if.end
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if.end:
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  ret i64 %add
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; CHECK: ret i64
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}
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; CHECK-LABEL: @test4(
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; Should be able to form an i8 sadd computed in an i32.
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define zeroext i8 @test4(i8 signext %a, i8 signext %b) nounwind ssp {
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entry:
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  %conv = sext i8 %a to i32
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  %conv2 = sext i8 %b to i32
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  %add = add nsw i32 %conv2, %conv
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  %add4 = add nsw i32 %add, 128
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  %cmp = icmp ugt i32 %add4, 255
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  br i1 %cmp, label %if.then, label %if.end
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; CHECK: llvm.sadd.with.overflow.i8
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if.then:                                          ; preds = %entry
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  tail call void @throwAnExceptionOrWhatever() nounwind
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  unreachable
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if.end:                                           ; preds = %entry
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  %conv7 = trunc i32 %add to i8
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  ret i8 %conv7
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; CHECK: ret i8
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}
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; CHECK-LABEL: @test8(
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; PR11438
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; This is @test1, but the operands are not sign-extended.  Make sure
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; we don't transform this case.
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define i32 @test8(i64 %a, i64 %b) nounwind ssp {
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entry:
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; CHECK-NOT: llvm.sadd
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; CHECK: add i64 %a, %b
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; CHECK-NOT: llvm.sadd
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; CHECK: ret
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  %add = add i64 %a, %b
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  %add.off = add i64 %add, 2147483648
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  %0 = icmp ugt i64 %add.off, 4294967295
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  br i1 %0, label %if.then, label %if.end
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if.then:
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  tail call void @throwAnExceptionOrWhatever() nounwind
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  br label %if.end
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if.end:
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  %conv9 = trunc i64 %add to i32
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  ret i32 %conv9
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}
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