1; REQUIRES: asserts 2; RUN: llc < %s -O3 -mtriple=x86_64-- -mcpu=core2 -stress-ivchain | FileCheck %s -check-prefix=X64 3; RUN: llc < %s -O3 -mtriple=i686-- -mcpu=core2 -stress-ivchain | FileCheck %s -check-prefix=X86 4 5; @sharedidx is an unrolled variant of this loop: 6; for (unsigned long i = 0; i < len; i += s) { 7; c[i] = a[i] + b[i]; 8; } 9; where 's' cannot be folded into the addressing mode. 10; 11; This is not quite profitable to chain. But with -stress-ivchain, we 12; can form three address chains in place of the shared induction 13; variable. 14 15; X64: sharedidx: 16; X64: %for.body.preheader 17; X64-NOT: leal ({{.*}},4) 18; X64: %for.body.1 19 20; X86: sharedidx: 21; X86: %for.body.2 22; X86: add 23; X86: add 24; X86: add 25; X86: add 26; X86: add 27; X86: %for.body.3 28define void @sharedidx(i8* nocapture %a, i8* nocapture %b, i8* nocapture %c, i32 %s, i32 %len) nounwind ssp { 29entry: 30 %cmp8 = icmp eq i32 %len, 0 31 br i1 %cmp8, label %for.end, label %for.body 32 33for.body: ; preds = %entry, %for.body.3 34 %i.09 = phi i32 [ %add5.3, %for.body.3 ], [ 0, %entry ] 35 %arrayidx = getelementptr inbounds i8, i8* %a, i32 %i.09 36 %0 = load i8, i8* %arrayidx, align 1 37 %conv6 = zext i8 %0 to i32 38 %arrayidx1 = getelementptr inbounds i8, i8* %b, i32 %i.09 39 %1 = load i8, i8* %arrayidx1, align 1 40 %conv27 = zext i8 %1 to i32 41 %add = add nsw i32 %conv27, %conv6 42 %conv3 = trunc i32 %add to i8 43 %arrayidx4 = getelementptr inbounds i8, i8* %c, i32 %i.09 44 store i8 %conv3, i8* %arrayidx4, align 1 45 %add5 = add i32 %i.09, %s 46 %cmp = icmp ult i32 %add5, %len 47 br i1 %cmp, label %for.body.1, label %for.end 48 49for.end: ; preds = %for.body, %for.body.1, %for.body.2, %for.body.3, %entry 50 ret void 51 52for.body.1: ; preds = %for.body 53 %arrayidx.1 = getelementptr inbounds i8, i8* %a, i32 %add5 54 %2 = load i8, i8* %arrayidx.1, align 1 55 %conv6.1 = zext i8 %2 to i32 56 %arrayidx1.1 = getelementptr inbounds i8, i8* %b, i32 %add5 57 %3 = load i8, i8* %arrayidx1.1, align 1 58 %conv27.1 = zext i8 %3 to i32 59 %add.1 = add nsw i32 %conv27.1, %conv6.1 60 %conv3.1 = trunc i32 %add.1 to i8 61 %arrayidx4.1 = getelementptr inbounds i8, i8* %c, i32 %add5 62 store i8 %conv3.1, i8* %arrayidx4.1, align 1 63 %add5.1 = add i32 %add5, %s 64 %cmp.1 = icmp ult i32 %add5.1, %len 65 br i1 %cmp.1, label %for.body.2, label %for.end 66 67for.body.2: ; preds = %for.body.1 68 %arrayidx.2 = getelementptr inbounds i8, i8* %a, i32 %add5.1 69 %4 = load i8, i8* %arrayidx.2, align 1 70 %conv6.2 = zext i8 %4 to i32 71 %arrayidx1.2 = getelementptr inbounds i8, i8* %b, i32 %add5.1 72 %5 = load i8, i8* %arrayidx1.2, align 1 73 %conv27.2 = zext i8 %5 to i32 74 %add.2 = add nsw i32 %conv27.2, %conv6.2 75 %conv3.2 = trunc i32 %add.2 to i8 76 %arrayidx4.2 = getelementptr inbounds i8, i8* %c, i32 %add5.1 77 store i8 %conv3.2, i8* %arrayidx4.2, align 1 78 %add5.2 = add i32 %add5.1, %s 79 %cmp.2 = icmp ult i32 %add5.2, %len 80 br i1 %cmp.2, label %for.body.3, label %for.end 81 82for.body.3: ; preds = %for.body.2 83 %arrayidx.3 = getelementptr inbounds i8, i8* %a, i32 %add5.2 84 %6 = load i8, i8* %arrayidx.3, align 1 85 %conv6.3 = zext i8 %6 to i32 86 %arrayidx1.3 = getelementptr inbounds i8, i8* %b, i32 %add5.2 87 %7 = load i8, i8* %arrayidx1.3, align 1 88 %conv27.3 = zext i8 %7 to i32 89 %add.3 = add nsw i32 %conv27.3, %conv6.3 90 %conv3.3 = trunc i32 %add.3 to i8 91 %arrayidx4.3 = getelementptr inbounds i8, i8* %c, i32 %add5.2 92 store i8 %conv3.3, i8* %arrayidx4.3, align 1 93 %add5.3 = add i32 %add5.2, %s 94 %cmp.3 = icmp ult i32 %add5.3, %len 95 br i1 %cmp.3, label %for.body, label %for.end 96} 97