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llvm-project/llvm/test/Transforms/LoopVectorize/gep_with_bitcast.ll

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LoopVectorizer - skip 'bitcast' between GEP and load. Skipping 'bitcast' in this case allows to vectorize load: %arrayidx = getelementptr inbounds double*, double** %in, i64 %indvars.iv %tmp53 = bitcast double** %arrayidx to i64* %tmp54 = load i64, i64* %tmp53, align 8 Differential Revision http://reviews.llvm.org/D14112 llvm-svn: 251907
2015-11-03 18:29:34 +08:00
; RUN: opt -S -loop-vectorize -instcombine -force-vector-width=4 < %s | FileCheck %s
target datalayout = "e-m:e-i64:64-i128:128-n32:64-S128"
; Vectorization of loop with bitcast between GEP and load
; Simplified source code:
;void foo (double** __restrict__ in, bool * __restrict__ res) {
;
; for (int i = 0; i < 4096; ++i)
; res[i] = ((unsigned long long)in[i] == 0);
;}
; CHECK-LABEL: @foo
; CHECK: vector.body
[LV] Don't widen trivial induction variables We currently always vectorize induction variables. However, if an induction variable is only used for counting loop iterations or computing addresses with getelementptr instructions, we don't need to do this. Vectorizing these trivial induction variables can create vector code that is difficult to simplify later on. This is especially true when the unroll factor is greater than one, and we create vector arithmetic when computing step vectors. With this patch, we check if an induction variable is only used for counting iterations or computing addresses, and if so, scalarize the arithmetic when computing step vectors instead. This allows for greater simplification. This patch addresses the suboptimal pointer arithmetic sequence seen in PR27881. Reference: https://llvm.org/bugs/show_bug.cgi?id=27881 Differential Revision: http://reviews.llvm.org/D21620 llvm-svn: 274627
2016-07-06 22:26:59 +08:00
; CHECK: %[[IV:.+]] = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
; CHECK: %[[v0:.+]] = getelementptr inbounds double*, double** %in, i64 %[[IV]]
; CHECK: %[[v1:.+]] = bitcast double** %[[v0]] to <4 x i64>*
; CHECK: %wide.load = load <4 x i64>, <4 x i64>* %[[v1]], align 8
; CHECK: icmp eq <4 x i64> %wide.load, zeroinitializer
LoopVectorizer - skip 'bitcast' between GEP and load. Skipping 'bitcast' in this case allows to vectorize load: %arrayidx = getelementptr inbounds double*, double** %in, i64 %indvars.iv %tmp53 = bitcast double** %arrayidx to i64* %tmp54 = load i64, i64* %tmp53, align 8 Differential Revision http://reviews.llvm.org/D14112 llvm-svn: 251907
2015-11-03 18:29:34 +08:00
; CHECK: br i1
define void @foo(double** noalias nocapture readonly %in, double** noalias nocapture readnone %out, i8* noalias nocapture %res) #0 {
entry:
br label %for.body
for.body:
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%arrayidx = getelementptr inbounds double*, double** %in, i64 %indvars.iv
%tmp53 = bitcast double** %arrayidx to i64*
%tmp54 = load i64, i64* %tmp53, align 8
%cmp1 = icmp eq i64 %tmp54, 0
%arrayidx3 = getelementptr inbounds i8, i8* %res, i64 %indvars.iv
%frombool = zext i1 %cmp1 to i8
store i8 %frombool, i8* %arrayidx3, align 1
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
%exitcond = icmp eq i64 %indvars.iv.next, 4096
br i1 %exitcond, label %for.end, label %for.body
for.end:
ret void
[LV] For some IVs, use vector phis instead of widening in the loop body Previously, whenever we needed a vector IV, we would create it on the fly, by splatting the scalar IV and adding a step vector. Instead, we can create a real vector IV. This tends to save a couple of instructions per iteration. This only changes the behavior for the most basic case - integer primary IVs with a constant step. Differential Revision: http://reviews.llvm.org/D20315 llvm-svn: 271410
2016-06-02 01:16:46 +08:00
}