32d9a386bf
Fix PR47390. The primary induction should be considered alive when folding tail by masking, because it will be used by said masking; even when it may otherwise appear useless: feeding only its own 'bump', which is correctly considered dead, and as the 'bump' of another induction variable, which may wrongfully want to consider its bump = the primary induction, dead. Differential Revision: https://reviews.llvm.org/D92017
72 lines
2.4 KiB
LLVM
72 lines
2.4 KiB
LLVM
; RUN: opt < %s -force-vector-width=2 -force-vector-interleave=2 -loop-vectorize -S | FileCheck %s
|
|
|
|
target datalayout = "e-m:e-i64:64-i128:128-n32:64-S128"
|
|
|
|
; CHECK-LABEL: @dead_instructions_01
|
|
;
|
|
; This test ensures that we don't generate trivially dead instructions prior to
|
|
; instruction simplification. We don't need to generate instructions
|
|
; corresponding to the original induction variable update or branch condition,
|
|
; since we rewrite the loop structure.
|
|
;
|
|
; CHECK: vector.body:
|
|
; CHECK: %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
|
|
; CHECK: %[[I0:.+]] = add i64 %index, 0
|
|
; CHECK: %[[I2:.+]] = add i64 %index, 2
|
|
; CHECK: getelementptr inbounds i64, i64* %a, i64 %[[I0]]
|
|
; CHECK: getelementptr inbounds i64, i64* %a, i64 %[[I2]]
|
|
; CHECK-NOT: add nuw nsw i64 %[[I0]], 1
|
|
; CHECK-NOT: add nuw nsw i64 %[[I2]], 1
|
|
; CHECK-NOT: icmp slt i64 {{.*}}, %n
|
|
; CHECK: %index.next = add i64 %index, 4
|
|
; CHECK: %[[CMP:.+]] = icmp eq i64 %index.next, %n.vec
|
|
; CHECK: br i1 %[[CMP]], label %middle.block, label %vector.body
|
|
;
|
|
define i64 @dead_instructions_01(i64 *%a, i64 %n) {
|
|
entry:
|
|
br label %for.body
|
|
|
|
for.body:
|
|
%i = phi i64 [ %i.next, %for.body ], [ 0, %entry ]
|
|
%r = phi i64 [ %tmp2, %for.body ], [ 0, %entry ]
|
|
%tmp0 = getelementptr inbounds i64, i64* %a, i64 %i
|
|
%tmp1 = load i64, i64* %tmp0, align 8
|
|
%tmp2 = add i64 %tmp1, %r
|
|
%i.next = add nuw nsw i64 %i, 1
|
|
%cond = icmp slt i64 %i.next, %n
|
|
br i1 %cond, label %for.body, label %for.end
|
|
|
|
for.end:
|
|
%tmp3 = phi i64 [ %tmp2, %for.body ]
|
|
ret i64 %tmp3
|
|
}
|
|
|
|
|
|
; CHECK-LABEL: @pr47390
|
|
;
|
|
; This test ensures that the primary induction is not considered dead when
|
|
; acting as the 'add' of another induction, and otherwise feeding only its own
|
|
; 'add' (recognized earlier as 'dead'), when the tail of the loop is folded by
|
|
; masking. Such masking uses the primary induction.
|
|
;
|
|
; CHECK: vector.body:
|
|
;
|
|
define void @pr47390(i32 *%a) {
|
|
entry:
|
|
br label %loop
|
|
|
|
exit:
|
|
ret void
|
|
|
|
loop:
|
|
%primary = phi i32 [ 0, %entry ], [ %primary_add, %loop ]
|
|
%use_primary = phi i32 [ -1, %entry ], [ %primary, %loop ]
|
|
%secondary = phi i32 [ 1, %entry ], [ %secondary_add, %loop ]
|
|
%primary_add = add i32 %primary, 1
|
|
%secondary_add = add i32 %secondary, 1
|
|
%gep = getelementptr inbounds i32, i32* %a, i32 %secondary
|
|
%load = load i32, i32* %gep, align 8
|
|
%cmp = icmp eq i32 %secondary, 5
|
|
br i1 %cmp, label %exit, label %loop
|
|
}
|