1; RUN: opt < %s -passes=loop-vectorize,dce,instcombine -force-vector-width=4 -S | FileCheck %s 2 3target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" 4 5; tests skipping iterations within a VF through break/continue/gotos. 6 7; The main difficulty in vectorizing these loops in test1,test2 and test3 is 8; safely speculating that the widened load of A[i] should not fault if the 9; scalarized loop does not fault. For example, the 10; original load in the scalar loop may not fault, but the last iteration of the 11; vectorized load can fault (if it crosses a page boudary for example). 12; This last vector iteration is where *one* of the 13; scalar iterations lead to the early exit. 14 15; int test(int *A, int Length) { 16; for (int i = 0; i < Length; i++) { 17; if (A[i] > 10.0) goto end; 18; A[i] = 0; 19; } 20; end: 21; return 0; 22; } 23; CHECK-LABEL: test1( 24; CHECK-NOT: <4 x i32> 25define i32 @test1(ptr nocapture %A, i32 %Length) { 26entry: 27 %cmp8 = icmp sgt i32 %Length, 0 28 br i1 %cmp8, label %for.body.preheader, label %end 29 30for.body.preheader: ; preds = %entry 31 br label %for.body 32 33for.body: ; preds = %for.body.preheader, %if.else 34 %indvars.iv = phi i64 [ %indvars.iv.next, %if.else ], [ 0, %for.body.preheader ] 35 %arrayidx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv 36 %0 = load i32, ptr %arrayidx, align 4, !tbaa !15 37 %cmp1 = icmp sgt i32 %0, 10 38 br i1 %cmp1, label %end.loopexit, label %if.else 39 40if.else: ; preds = %for.body 41 store i32 0, ptr %arrayidx, align 4, !tbaa !15 42 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 43 %1 = trunc i64 %indvars.iv.next to i32 44 %cmp = icmp slt i32 %1, %Length 45 br i1 %cmp, label %for.body, label %end.loopexit 46 47end.loopexit: ; preds = %if.else, %for.body 48 br label %end 49 50end: ; preds = %end.loopexit, %entry 51 ret i32 0 52} 53 54; We don't use anything from within the loop at the early exit path 55; so we do not need to know which iteration caused the early exit path. 56; bool test2(int *A, int Length, int K) { 57; for (int i = 0; i < Length; i++) { 58; if (A[i] == K) return true; 59; } 60; return false; 61; } 62; TODO: Today we do not vectorize this, but we could teach the vectorizer, once 63; the hard part of proving/speculating A[i:VF - 1] loads does not fault is handled by the 64; compiler/hardware. 65 66; CHECK-LABEL: test2( 67; CHECK-NOT: <4 x i32> 68define i32 @test2(ptr nocapture %A, i32 %Length, i32 %K) { 69entry: 70 %cmp8 = icmp sgt i32 %Length, 0 71 br i1 %cmp8, label %for.body.preheader, label %end 72 73for.body.preheader: ; preds = %entry 74 br label %for.body 75 76for.body: ; preds = %for.body.preheader, %if.else 77 %indvars.iv = phi i64 [ %indvars.iv.next, %if.else ], [ 0, %for.body.preheader ] 78 %arrayidx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv 79 %ld = load i32, ptr %arrayidx, align 4 80 %cmp1 = icmp eq i32 %ld, %K 81 br i1 %cmp1, label %end.loopexit, label %if.else 82 83if.else: ; preds = %for.body 84 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 85 %trunc = trunc i64 %indvars.iv.next to i32 86 %cmp = icmp slt i32 %trunc, %Length 87 br i1 %cmp, label %for.body, label %end.loopexit 88 89end.loopexit: ; preds = %if.else, %for.body 90 %result.lcssa = phi i32 [ 1, %for.body ], [ 0, %if.else ] 91 br label %end 92 93end: ; preds = %end.loopexit, %entry 94 %result = phi i32 [ %result.lcssa, %end.loopexit ], [ 0, %entry ] 95 ret i32 %result 96} 97 98; We use the IV in the early exit 99; so we need to know which iteration caused the early exit path. 100; int test3(int *A, int Length, int K) { 101; for (int i = 0; i < Length; i++) { 102; if (A[i] == K) return i; 103; } 104; return -1; 105; } 106; TODO: Today we do not vectorize this, but we could teach the vectorizer (once 107; we handle the speculation safety of the widened load). 108; CHECK-LABEL: test3( 109; CHECK-NOT: <4 x i32> 110define i32 @test3(ptr nocapture %A, i32 %Length, i32 %K) { 111entry: 112 %cmp8 = icmp sgt i32 %Length, 0 113 br i1 %cmp8, label %for.body.preheader, label %end 114 115for.body.preheader: ; preds = %entry 116 br label %for.body 117 118for.body: ; preds = %for.body.preheader, %if.else 119 %indvars.iv = phi i64 [ %indvars.iv.next, %if.else ], [ 0, %for.body.preheader ] 120 %arrayidx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv 121 %ld = load i32, ptr %arrayidx, align 4 122 %cmp1 = icmp eq i32 %ld, %K 123 br i1 %cmp1, label %end.loopexit, label %if.else 124 125if.else: ; preds = %for.body 126 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 127 %trunc = trunc i64 %indvars.iv.next to i32 128 %cmp = icmp slt i32 %trunc, %Length 129 br i1 %cmp, label %for.body, label %end.loopexit 130 131end.loopexit: ; preds = %if.else, %for.body 132 %result.lcssa = phi i64 [ %indvars.iv, %for.body ], [ -1, %if.else ] 133 %res.trunc = trunc i64 %result.lcssa to i32 134 br label %end 135 136end: ; preds = %end.loopexit, %entry 137 %result = phi i32 [ %res.trunc, %end.loopexit ], [ -1, %entry ] 138 ret i32 %result 139} 140 141; bool test4(int *A, int Length, int K, int J) { 142; for (int i = 0; i < Length; i++) { 143; if (A[i] == K) continue; 144; A[i] = J; 145; } 146; } 147; For this test, we vectorize and generate predicated stores to A[i]. 148; CHECK-LABEL: test4( 149; CHECK: <4 x i32> 150define void @test4(ptr nocapture %A, i32 %Length, i32 %K, i32 %J) { 151entry: 152 %cmp8 = icmp sgt i32 %Length, 0 153 br i1 %cmp8, label %for.body.preheader, label %end.loopexit 154 155for.body.preheader: ; preds = %entry 156 br label %for.body 157 158for.body: ; preds = %for.body.preheader, %if.else 159 %indvars.iv = phi i64 [ %indvars.iv.next, %latch ], [ 0, %for.body.preheader ] 160 %arrayidx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv 161 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 162 %trunc = trunc i64 %indvars.iv.next to i32 163 %ld = load i32, ptr %arrayidx, align 4 164 %cmp1 = icmp eq i32 %ld, %K 165 br i1 %cmp1, label %latch, label %if.else 166 167if.else: 168 store i32 %J, ptr %arrayidx, align 4 169 br label %latch 170 171latch: ; preds = %for.body 172 %cmp = icmp slt i32 %trunc, %Length 173 br i1 %cmp, label %for.body, label %end.loopexit 174 175end.loopexit: ; preds = %if.else, %for.body 176 ret void 177} 178!15 = !{!16, !16, i64 0} 179!16 = !{!"int", !17, i64 0} 180!17 = !{!"omnipotent char", !18, i64 0} 181!18 = !{!"Simple C/C++ TBAA"} 182