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	Reduce integer multiplication by a constant of the form k*2^c, where k is in {3,5,9} into a lea + shl. Previously it was only done for imulq on 64-bit platforms, but it makes sense for imull and 32-bit as well.
Differential Revision: http://reviews.llvm.org/D7196
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227308 91177308-0d34-0410-b5e6-96231b3b80d8
		
	
		
			
				
	
	
		
			111 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			LLVM
		
	
	
	
	
	
			
		
		
	
	
			111 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			LLVM
		
	
	
	
	
	
| ; RUN: llc < %s -mtriple=x86_64-pc-linux-gnu | FileCheck %s --check-prefix=X64
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| ; RUN: llc < %s -mtriple=x86_64-pc-linux-gnux32 | FileCheck %s --check-prefix=X64
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| ; RUN: llc < %s -mtriple=i686-pc-linux | FileCheck %s --check-prefix=X86
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| 
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| define i32 @mul4_32(i32 %A) {
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| ; X64-LABEL: mul4_32:
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| ; X64: leal
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| ; X86-LABEL: mul4_32:
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| ; X86: shll
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|     %mul = mul i32 %A, 4
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|     ret i32 %mul
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| }
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| 
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| define i64 @mul4_64(i64 %A) {
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| ; X64-LABEL: mul4_64:
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| ; X64: leaq
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| ; X86-LABEL: mul4_64:
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| ; X86: shldl
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| ; X86: shll
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|     %mul = mul i64 %A, 4
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|     ret i64 %mul
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| }
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| 
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| define i32 @mul4096_32(i32 %A) {
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| ; X64-LABEL: mul4096_32:
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| ; X64: shll
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| ; X86-LABEL: mul4096_32:
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| ; X86: shll
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|     %mul = mul i32 %A, 4096
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|     ret i32 %mul
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| }
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| 
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| define i64 @mul4096_64(i64 %A) {
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| ; X64-LABEL: mul4096_64:
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| ; X64: shlq
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| ; X86-LABEL: mul4096_64:
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| ; X86: shldl
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| ; X86: shll
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|     %mul = mul i64 %A, 4096
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|     ret i64 %mul
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| }
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| 
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| define i32 @mulmin4096_32(i32 %A) {
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| ; X64-LABEL: mulmin4096_32:
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| ; X64: shll
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| ; X64-NEXT: negl
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| ; X86-LABEL: mulmin4096_32:
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| ; X86: shll
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| ; X86-NEXT: negl
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|     %mul = mul i32 %A, -4096
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|     ret i32 %mul
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| }
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| 
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| define i64 @mulmin4096_64(i64 %A) {
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| ; X64-LABEL: mulmin4096_64:
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| ; X64: shlq
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| ; X64-NEXT: negq
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| ; X86-LABEL: mulmin4096_64:
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| ; X86: shldl
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| ; X86-NEXT: shll
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| ; X86-NEXT: xorl
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| ; X86-NEXT: negl
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| ; X86-NEXT: sbbl
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|     %mul = mul i64 %A, -4096
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|     ret i64 %mul
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| }
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| 
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| define i32 @mul3_32(i32 %A) {
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| ; X64-LABEL: mul3_32:
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| ; X64: leal
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| ; X86-LABEL: mul3_32:
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| ; But why?!
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| ; X86: imull
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|     %mul = mul i32 %A, 3
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|     ret i32 %mul
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| }
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| 
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| define i64 @mul3_64(i64 %A) {
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| ; X64-LABEL: mul3_64:
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| ; X64: leaq
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| ; X86-LABEL: mul3_64:
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| ; X86: mull
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| ; X86-NEXT: imull
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|     %mul = mul i64 %A, 3
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|     ret i64 %mul
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| }
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| 
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| define i32 @mul40_32(i32 %A) {
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| ; X64-LABEL: mul40_32:
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| ; X64: shll
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| ; X64-NEXT: leal
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| ; X86-LABEL: mul40_32:
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| ; X86: shll
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| ; X86-NEXT: leal
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|     %mul = mul i32 %A, 40
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|     ret i32 %mul
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| }
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| 
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| define i64 @mul40_64(i64 %A) {
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| ; X64-LABEL: mul40_64:
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| ; X64: shlq
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| ; X64-NEXT: leaq
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| ; X86-LABEL: mul40_64:
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| ; X86: leal
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| ; X86-NEXT: movl
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| ; X86-NEXT: mull
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| ; X86-NEXT: leal
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|     %mul = mul i64 %A, 40
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|     ret i64 %mul
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| }
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