Mercurial > hg > Members > tobaru > cbc > CbC_llvm
view test/CodeGen/X86/fold-and-shift.ll @ 33:e4204d083e25
LLVM 3.5
author | Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> |
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date | Thu, 12 Dec 2013 14:32:10 +0900 |
parents | 95c75e76d11b |
children | afa8332a0e37 |
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; RUN: llc < %s -march=x86 | FileCheck %s define i32 @t1(i8* %X, i32 %i) { ; CHECK-LABEL: t1: ; CHECK-NOT: and ; CHECK: movzbl ; CHECK: movl (%{{...}},%{{...}},4), ; CHECK: ret entry: %tmp2 = shl i32 %i, 2 %tmp4 = and i32 %tmp2, 1020 %tmp7 = getelementptr i8* %X, i32 %tmp4 %tmp78 = bitcast i8* %tmp7 to i32* %tmp9 = load i32* %tmp78 ret i32 %tmp9 } define i32 @t2(i16* %X, i32 %i) { ; CHECK-LABEL: t2: ; CHECK-NOT: and ; CHECK: movzwl ; CHECK: movl (%{{...}},%{{...}},4), ; CHECK: ret entry: %tmp2 = shl i32 %i, 1 %tmp4 = and i32 %tmp2, 131070 %tmp7 = getelementptr i16* %X, i32 %tmp4 %tmp78 = bitcast i16* %tmp7 to i32* %tmp9 = load i32* %tmp78 ret i32 %tmp9 } define i32 @t3(i16* %i.ptr, i32* %arr) { ; This case is tricky. The lshr followed by a gep will produce a lshr followed ; by an and to remove the low bits. This can be simplified by doing the lshr by ; a greater constant and using the addressing mode to scale the result back up. ; To make matters worse, because of the two-phase zext of %i and their reuse in ; the function, the DAG can get confusing trying to re-use both of them and ; prevent easy analysis of the mask in order to match this. ; CHECK-LABEL: t3: ; CHECK-NOT: and ; CHECK: shrl ; CHECK: addl (%{{...}},%{{...}},4), ; CHECK: ret entry: %i = load i16* %i.ptr %i.zext = zext i16 %i to i32 %index = lshr i32 %i.zext, 11 %val.ptr = getelementptr inbounds i32* %arr, i32 %index %val = load i32* %val.ptr %sum = add i32 %val, %i.zext ret i32 %sum } define i32 @t4(i16* %i.ptr, i32* %arr) { ; A version of @t3 that has more zero extends and more re-use of intermediate ; values. This exercise slightly different bits of canonicalization. ; CHECK-LABEL: t4: ; CHECK-NOT: and ; CHECK: shrl ; CHECK: addl (%{{...}},%{{...}},4), ; CHECK: ret entry: %i = load i16* %i.ptr %i.zext = zext i16 %i to i32 %index = lshr i32 %i.zext, 11 %index.zext = zext i32 %index to i64 %val.ptr = getelementptr inbounds i32* %arr, i64 %index.zext %val = load i32* %val.ptr %sum.1 = add i32 %val, %i.zext %sum.2 = add i32 %sum.1, %index ret i32 %sum.2 }