65 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			65 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			LLVM
		
	
	
	
| ; RUN: opt -S -instcombine < %s | FileCheck %s
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| target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32"
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| target triple = "i386-apple-darwin10.0.0"
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| 
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| ; CHECK-LABEL: define void @fu1(
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| define void @fu1(i32 %parm) nounwind ssp {
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|   %1 = alloca i32, align 4
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| ; CHECK: alloca double*
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|   %ptr = alloca double*, align 4
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|   store i32 %parm, i32* %1, align 4
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|   store double* null, double** %ptr, align 4
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|   %2 = load i32, i32* %1, align 4
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|   %3 = icmp ne i32 %2, 0
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|   br i1 %3, label %4, label %10
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| 
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| ; <label>:4                                       ; preds = %0
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|   %5 = load i32, i32* %1, align 4
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|   %6 = shl nsw i32 %5, 3
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| ; With "nsw", the alloca and its bitcast can be fused:
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|   %7 = add nsw i32 %6, 2048
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| ;  CHECK: alloca double
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|   %8 = alloca i8, i32 %7
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|   %9 = bitcast i8* %8 to double*
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| ; CHECK-NEXT: store double*
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|   store double* %9, double** %ptr, align 4
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|   br label %10
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| ; <label>:10                                      ; preds = %4, %0
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|   %11 = load double*, double** %ptr, align 4
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|   call void @bar(double* %11)
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| ; CHECK: ret
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|   ret void
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| }
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| 
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| declare void @bar(double*)
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| 
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| ; CHECK-LABEL: define void @fu2(
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| define void @fu2(i32 %parm) nounwind ssp {
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|   %1 = alloca i32, align 4
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|   %ptr = alloca double*, align 4
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|   store i32 %parm, i32* %1, align 4
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|   store double* null, double** %ptr, align 4
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|   %2 = load i32, i32* %1, align 4
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|   %3 = icmp ne i32 %2, 0
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|   br i1 %3, label %4, label %10
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| 
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| ; <label>:4                                       ; preds = %0
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|   %5 = load i32, i32* %1, align 4
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|   %6 = mul nsw i32 %5, 8
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| ; Without "nsw", the alloca and its bitcast cannot be fused:
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|   %7 = add  i32 %6, 2048
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| ; CHECK: alloca i8
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|   %8 = alloca i8, i32 %7
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| ; CHECK-NEXT: bitcast double**
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| ; CHECK-NEXT: store i8*
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|   %9 = bitcast i8* %8 to double*
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|   store double* %9, double** %ptr, align 4
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|   br label %10
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| 
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| ; <label>:10                                      ; preds = %4, %0
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|   %11 = load double*, double** %ptr, align 4
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|   call void @bar(double* %11)
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|   ret void
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| }
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| 
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