f562fc8dbf
Teach LICM to hoist stores out of loops when the store writes to a location otherwise unused in the loop, writes a value which is invariant, and is guaranteed to execute if the loop is entered. Worth noting is that this transformation is partially overlapping with the existing promotion transformation. Reasons this is worthwhile anyway include: * For multi-exit loops, this doesn't require duplication of the store. * It kicks in for case where we can't prove we exit through a normal exit (i.e. we may throw), but can prove the store executes before that possible side exit. Differential Revision: https://reviews.llvm.org/D50925 llvm-svn: 340974
111 lines
4.0 KiB
LLVM
111 lines
4.0 KiB
LLVM
; RUN: opt < %s -licm -S | FileCheck %s
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; RUN: opt -aa-pipeline=basic-aa -passes='require<aa>,require<targetir>,require<scalar-evolution>,require<opt-remark-emit>,loop(licm)' < %s -S | FileCheck %s
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target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
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target triple = "i386-pc-windows-msvc18.0.0"
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define void @test1(i32* %s, i1 %b) personality i32 (...)* @__CxxFrameHandler3 {
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entry:
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br label %while.cond
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while.cond: ; preds = %while.body, %entry
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%0 = call i32 @pure_computation()
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br i1 %b, label %try.cont, label %while.body
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while.body: ; preds = %while.cond
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invoke void @may_throw()
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to label %while.cond unwind label %catch.dispatch
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catch.dispatch: ; preds = %while.body
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%.lcssa1 = phi i32 [ %0, %while.body ]
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%cs = catchswitch within none [label %catch] unwind to caller
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catch: ; preds = %catch.dispatch
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%cp = catchpad within %cs [i8* null, i32 64, i8* null]
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store i32 %.lcssa1, i32* %s
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catchret from %cp to label %try.cont
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try.cont: ; preds = %catch, %while.cond
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ret void
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}
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; CHECK-LABEL: define void @test1(
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; CHECK: %[[CALL:.*]] = call i32 @pure_computation()
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; CHECK: phi i32 [ %[[CALL]]
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define void @test2(i32* %s, i1 %b) personality i32 (...)* @__CxxFrameHandler3 {
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entry:
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br label %while.cond
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while.cond: ; preds = %while.body, %entry
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%0 = call i32 @pure_computation()
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br i1 %b, label %try.cont, label %while.body
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while.body: ; preds = %while.cond
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invoke void @may_throw()
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to label %while.cond unwind label %catch.dispatch
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catch.dispatch: ; preds = %while.body
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%.lcssa1 = phi i32 [ %0, %while.body ]
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%cp = cleanuppad within none []
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store i32 %.lcssa1, i32* %s
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cleanupret from %cp unwind to caller
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try.cont: ; preds = %catch, %while.cond
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ret void
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}
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; CHECK-LABEL: define void @test2(
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; CHECK: %[[CP:.*]] = cleanuppad within none []
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; CHECK-NEXT: %[[CALL:.*]] = call i32 @pure_computation() [ "funclet"(token %[[CP]]) ]
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; CHECK-NEXT: store i32 %[[CALL]], i32* %s
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; CHECK-NEXT: cleanupret from %[[CP]] unwind to caller
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define void @test3(i1 %a, i1 %b, i1 %c) personality i32 (...)* @__CxxFrameHandler3 {
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entry:
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%.frame = alloca i8, align 4
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%.frame2 = alloca i8, align 4
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%bc = bitcast i8* %.frame to i32*
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%bc2 = bitcast i8* %.frame2 to i32*
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br i1 %a, label %try.success.or.caught, label %forbody
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catch.object.Throwable: ; preds = %catch.dispatch
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%cp = catchpad within %cs [i8* null, i32 64, i8* null]
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unreachable
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try.success.or.caught: ; preds = %forcond.backedge, %0
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ret void
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postinvoke: ; preds = %forbody
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br i1 %b, label %else, label %forcond.backedge
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forcond.backedge: ; preds = %else, %postinvoke
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br i1 %c, label %try.success.or.caught, label %forbody
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catch.dispatch: ; preds = %else, %forbody
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%cs = catchswitch within none [label %catch.object.Throwable] unwind to caller
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forbody: ; preds = %forcond.backedge, %0
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store i32 1, i32* %bc, align 4
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store i32 2, i32* %bc2, align 4
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invoke void @may_throw()
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to label %postinvoke unwind label %catch.dispatch
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else: ; preds = %postinvoke
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invoke void @may_throw()
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to label %forcond.backedge unwind label %catch.dispatch
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}
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; CHECK-LABEL: define void @test3(
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; CHECK-LABEL: forbody.preheader:
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; CHECK: store i32 1, i32* %bc, align 4
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; CHECK: store i32 2, i32* %bc2, align 4
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; CHECK: catchswitch within none
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; CHECK-LABEL: forbody:
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declare void @may_throw()
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declare i32 @pure_computation() nounwind argmemonly readonly
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declare i32 @__CxxFrameHandler3(...)
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