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llvm-project/llvm/test/Transforms/LICM/store-hoisting.ll

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[BasicAA] Rename deprecated -basicaa to -basic-aa Follow-up to D82607 Revert an accidental change (empty.ll) of D82683
2020-06-27 11:41:37 +08:00
; RUN: opt -S -basic-aa -licm -enable-mssa-loop-dependency=false %s | FileCheck -check-prefixes=CHECK,AST %s
; RUN: opt -S -basic-aa -licm -enable-mssa-loop-dependency=true %s | FileCheck -check-prefixes=CHECK,MSSA %s
Revert "Temporarily Revert "Add basic loop fusion pass."" The reversion apparently deleted the test/Transforms directory. Will be re-reverting again. llvm-svn: 358552
2019-04-17 12:52:47 +08:00
; RUN: opt -aa-pipeline=basic-aa -passes='require<aa>,require<targetir>,require<scalar-evolution>,require<opt-remark-emit>,loop(licm)' < %s -S | FileCheck -check-prefixes=CHECK,AST %s
[LoopPassManager + MemorySSA] Only enable use of MemorySSA for LPMs known to preserve it. Summary: Add a flag to the FunctionToLoopAdaptor that allows enabling MemorySSA only for the loop pass managers that are known to preserve it. If an LPM is known to have only loop transforms that *all* preserve MemorySSA, then use MemorySSA if `EnableMSSALoopDependency` is set. If an LPM has loop passes that do not preserve MemorySSA, then the flag passed is `false`, regardless of the value of `EnableMSSALoopDependency`. When using a custom loop pass pipeline via `passes=...`, use keyword `loop` vs `loop-mssa` to use MemorySSA in that LPM. If a loop that does not preserve MemorySSA is added while using the `loop-mssa` keyword, that's an error. Add the new `loop-mssa` keyword to a few tests where a difference occurs when enabling MemorySSA. Reviewers: chandlerc Subscribers: mehdi_amini, Prazek, george.burgess.iv, sanjoy.google, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66376 llvm-svn: 369548
2019-08-22 01:00:57 +08:00
; RUN: opt -aa-pipeline=basic-aa -passes='require<aa>,require<targetir>,require<scalar-evolution>,require<opt-remark-emit>,loop-mssa(licm)' < %s -S | FileCheck -check-prefixes=CHECK,MSSA %s
Revert "Temporarily Revert "Add basic loop fusion pass."" The reversion apparently deleted the test/Transforms directory. Will be re-reverting again. llvm-svn: 358552
2019-04-17 12:52:47 +08:00
define void @test(i32* %loc) {
; CHECK-LABEL: @test
; CHECK-LABEL: entry:
; CHECK: store i32 0, i32* %loc
; CHECK-LABEL: loop:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
store i32 0, i32* %loc
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
define void @test_multiexit(i32* %loc, i1 %earlycnd) {
; CHECK-LABEL: @test_multiexit
; CHECK-LABEL: entry:
; CHECK: store i32 0, i32* %loc
; CHECK-LABEL: loop:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %backedge]
store i32 0, i32* %loc
%iv.next = add i32 %iv, 1
br i1 %earlycnd, label %exit1, label %backedge
backedge:
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit2
exit1:
ret void
exit2:
ret void
}
define i32* @false_negative_2use(i32* %loc) {
; CHECK-LABEL: @false_negative_2use
; AST-LABEL: exit:
; AST: store i32 0, i32* %loc
; MSSA-LABEL: entry:
; MSSA: store i32 0, i32* %loc
; MSSA-LABEL: loop:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
store i32 0, i32* %loc
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret i32* %loc
}
define void @neg_lv_value(i32* %loc) {
; CHECK-LABEL: @neg_lv_value
; CHECK-LABEL: exit:
; CHECK: store i32 %iv.lcssa, i32* %loc
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
store i32 %iv, i32* %loc
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
define void @neg_lv_addr(i32* %loc) {
; CHECK-LABEL: @neg_lv_addr
; CHECK-LABEL: loop:
; CHECK: store i32 0, i32* %p
; CHECK-LABEL: exit:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
%p = getelementptr i32, i32* %loc, i32 %iv
store i32 0, i32* %p
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
define void @neg_mod(i32* %loc) {
; CHECK-LABEL: @neg_mod
; CHECK-LABEL: exit:
; CHECK: store i32 %iv.lcssa, i32* %loc
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
store i32 0, i32* %loc
store i32 %iv, i32* %loc
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
; Hoisting the store is actually valid here, as it dominates the load.
define void @neg_ref(i32* %loc) {
; CHECK-LABEL: @neg_ref
; CHECK-LABEL: exit1:
; CHECK: store i32 0, i32* %loc
; CHECK-LABEL: exit2:
; CHECK: store i32 0, i32* %loc
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %backedge]
store i32 0, i32* %loc
%v = load i32, i32* %loc
%earlycnd = icmp eq i32 %v, 198
br i1 %earlycnd, label %exit1, label %backedge
backedge:
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit2
exit1:
ret void
exit2:
ret void
}
; Hoisting the store here leads to a miscompile.
define void @neg_ref2(i32* %loc) {
; CHECK-LABEL: @neg_ref2
; CHECK-LABEL: exit1:
; CHECK: store i32 0, i32* %loc
; CHECK-LABEL: exit2:
; CHECK: store i32 0, i32* %loc
entry:
store i32 198, i32* %loc
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %backedge]
%v = load i32, i32* %loc
store i32 0, i32* %loc
%earlycnd = icmp eq i32 %v, 198
br i1 %earlycnd, label %exit1, label %backedge
backedge:
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit2
exit1:
ret void
exit2:
ret void
}
declare void @modref()
define void @neg_modref(i32* %loc) {
; CHECK-LABEL: @neg_modref
; CHECK-LABEL: loop:
; CHECK: store i32 0, i32* %loc
; CHECK-LABEL: exit:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
store i32 0, i32* %loc
call void @modref()
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
define void @neg_fence(i32* %loc) {
; CHECK-LABEL: @neg_fence
; CHECK-LABEL: loop:
; CHECK: store i32 0, i32* %loc
; CHECK-LABEL: exit:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
store i32 0, i32* %loc
fence seq_cst
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
define void @neg_volatile(i32* %loc) {
; CHECK-LABEL: @neg_volatile
; CHECK-LABEL: loop:
; CHECK: store volatile i32 0, i32* %loc
; CHECK-LABEL: exit:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
store volatile i32 0, i32* %loc
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
define void @neg_release(i32* %loc) {
; CHECK-LABEL: @neg_release
; CHECK-LABEL: loop:
; CHECK: store atomic i32 0, i32* %loc release, align 4
; CHECK-LABEL: exit:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
store atomic i32 0, i32* %loc release, align 4
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
define void @neg_seq_cst(i32* %loc) {
; CHECK-LABEL: @neg_seq_cst
; CHECK-LABEL: loop:
; CHECK: store atomic i32 0, i32* %loc seq_cst, align 4
; CHECK-LABEL: exit:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
store atomic i32 0, i32* %loc seq_cst, align 4
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
declare void @maythrow() inaccessiblememonly
define void @neg_early_exit(i32* %loc) {
; CHECK-LABEL: @neg_early_exit
; CHECK-LABEL: body:
; CHECK: store i32 0, i32* %loc
; CHECK-LABEL: exit:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %body]
%is_null = icmp eq i32* %loc, null
br i1 %is_null, label %exit, label %body
body:
call void @maythrow()
store i32 0, i32* %loc
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
define void @neg_early_throw(i32* %loc) {
; CHECK-LABEL: @neg_early_throw
; CHECK-LABEL: loop:
; CHECK: store i32 0, i32* %loc
; CHECK-LABEL: exit:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
call void @maythrow()
store i32 0, i32* %loc
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
define void @test_late_throw(i32* %loc) {
; CHECK-LABEL: @test_late_throw
; CHECK-LABEL: entry:
; CHECK: store i32 0, i32* %loc
; CHECK-LABEL: loop:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
store i32 0, i32* %loc
call void @maythrow()
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
; TODO: could validly hoist the store here since we know what value
; the load must observe.
define i32 @test_dominated_read(i32* %loc) {
; CHECK-LABEL: @test_dominated_read
[LICM & MSSA] Limit unsafe sinking and hoisting. Summary: The getClobberingMemoryAccess API checks for clobbering accesses in a loop by walking the backedge. This may check if a memory access is being clobbered by the loop in a previous iteration, depending how smart AA got over the course of the updates in MemorySSA (it does not occur when built from scratch). If no clobbering access is found inside the loop, it will optimize to an access outside the loop. This however does not mean that access is safe to sink. Given: ``` for i load a[i] store a[i] ``` The access corresponding to the load can be optimized to outside the loop, and the load can be hoisted. But it is incorrect to sink it. In order to sink the load, we'd need to check no Def clobbers the Use in the same iteration. With this patch we currently restrict sinking to either Defs not existing in the loop, or Defs preceding the load in the same block. An easy extension is to ensure the load (Use) post-dominates all Defs. Caught by PR42294. This issue also shed light on the converse problem: hoisting stores in this same scenario would be illegal. With this patch we restrict hoisting of stores to the case when their corresponding Defs are dominating all Uses in the loop. Reviewers: george.burgess.iv Subscribers: jlebar, Prazek, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D63582 llvm-svn: 363982
2019-06-21 05:09:09 +08:00
; MSSA-LABEL: entry:
; MSSA: store i32 0, i32* %loc
; MSSA-LABEL: loop:
; AST-LABEL: exit:
; AST: store i32 0, i32* %loc
Revert "Temporarily Revert "Add basic loop fusion pass."" The reversion apparently deleted the test/Transforms directory. Will be re-reverting again. llvm-svn: 358552
2019-04-17 12:52:47 +08:00
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
store i32 0, i32* %loc
%reload = load i32, i32* %loc
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret i32 %reload
}
; TODO: could validly hoist the store since we already hoisted the load and
; it's no longer in the loop.
define i32 @test_dominating_read(i32* %loc) {
; CHECK-LABEL: @test_dominating_read
; CHECK-LABEL: exit:
; CHECK: store i32 0, i32* %loc
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
%reload = load i32, i32* %loc
store i32 0, i32* %loc
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret i32 %reload
}
declare void @readonly() readonly
; TODO: can legally hoist since value read by call is known
define void @test_dominated_readonly(i32* %loc) {
; CHECK-LABEL: @test_dominated_readonly
; CHECK-LABEL: loop:
; CHECK: store i32 0, i32* %loc
; CHECK-LABEL: exit:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
store i32 0, i32* %loc
call void @readonly()
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
; While technically possible to hoist the store to %loc, this runs across
; a funemental limitation of alias sets since both stores and the call are
; within the same alias set and we can't distinguish them cheaply.
define void @test_aliasset_fn(i32* %loc, i32* %loc2) {
; CHECK-LABEL: @test_aliasset_fn
; CHECK-LABEL: loop:
; CHECK: store i32 0, i32* %loc
; CHECK-LABEL: exit:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %loop]
store i32 0, i32* %loc
call void @readonly()
store i32 %iv, i32* %loc2
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
; If we can't tell if the value is read before the write, we can't hoist the
; write over the potential read (since we don't know the value read)
define void @neg_may_read(i32* %loc, i1 %maybe) {
; CHECK-LABEL: @neg_may_read
; CHECK-LABEL: loop:
; CHECK: store i32 0, i32* %loc
; CHECK-LABEL: exit:
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %merge]
;; maybe is a placeholder for an unanalyzable condition
br i1 %maybe, label %taken, label %merge
taken:
call void @readonly()
br label %merge
merge:
store i32 0, i32* %loc
%iv.next = add i32 %iv, 1
%cmp = icmp slt i32 %iv, 200
br i1 %cmp, label %loop, label %exit
exit:
ret void
}