llvm-project/llvm/test/Transforms/CodeGenPrepare/basic.ll

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; RUN: opt -codegenprepare -S < %s | FileCheck %s
target 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"
target triple = "x86_64-apple-darwin10.0.0"
; CHECK-LABEL: @test1(
; objectsize should fold to a constant, which causes the branch to fold to an
; uncond branch. Next, we fold the control flow alltogether.
; rdar://8785296
define i32 @test1(i8* %ptr) nounwind ssp noredzone align 2 {
entry:
%0 = tail call i64 @llvm.objectsize.i64(i8* %ptr, i1 false, i1 false)
%1 = icmp ugt i64 %0, 3
br i1 %1, label %T, label %trap
Generalize MergeBlockIntoPredecessor. Replace uses of MergeBasicBlockIntoOnlyPred. Summary: Two utils methods have essentially the same functionality. This is an attempt to merge them into one. 1. lib/Transforms/Utils/Local.cpp : MergeBasicBlockIntoOnlyPred 2. lib/Transforms/Utils/BasicBlockUtils.cpp : MergeBlockIntoPredecessor Prior to the patch: 1. MergeBasicBlockIntoOnlyPred Updates either DomTree or DeferredDominance Moves all instructions from Pred to BB, deletes Pred Asserts BB has single predecessor If address was taken, replace the block address with constant 1 (?) 2. MergeBlockIntoPredecessor Updates DomTree, LoopInfo and MemoryDependenceResults Moves all instruction from BB to Pred, deletes BB Returns if doesn't have a single predecessor Returns if BB's address was taken After the patch: Method 2. MergeBlockIntoPredecessor is attempting to become the new default: Updates DomTree or DeferredDominance, and LoopInfo and MemoryDependenceResults Moves all instruction from BB to Pred, deletes BB Returns if doesn't have a single predecessor Returns if BB's address was taken Uses of MergeBasicBlockIntoOnlyPred that need to be replaced: 1. lib/Transforms/Scalar/LoopSimplifyCFG.cpp Updated in this patch. No challenges. 2. lib/CodeGen/CodeGenPrepare.cpp Updated in this patch. i. eliminateFallThrough is straightforward, but I added using a temporary array to avoid the iterator invalidation. ii. eliminateMostlyEmptyBlock(s) methods also now use a temporary array for blocks Some interesting aspects: - Since Pred is not deleted (BB is), the entry block does not need updating. - The entry block was being updated with the deleted block in eliminateMostlyEmptyBlock. Added assert to make obvious that BB=SinglePred. - isMergingEmptyBlockProfitable assumes BB is the one to be deleted. - eliminateMostlyEmptyBlock(BB) does not delete BB on one path, it deletes its unique predecessor instead. - adding some test owner as subscribers for the interesting tests modified: test/CodeGen/X86/avx-cmp.ll test/CodeGen/AMDGPU/nested-loop-conditions.ll test/CodeGen/AMDGPU/si-annotate-cf.ll test/CodeGen/X86/hoist-spill.ll test/CodeGen/X86/2006-11-17-IllegalMove.ll 3. lib/Transforms/Scalar/JumpThreading.cpp Not covered in this patch. It is the only use case using the DeferredDominance. I would defer to Brian Rzycki to make this replacement. Reviewers: chandlerc, spatel, davide, brzycki, bkramer, javed.absar Subscribers: qcolombet, sanjoy, nemanjai, nhaehnle, jlebar, tpr, kbarton, RKSimon, wmi, arsenm, llvm-commits Differential Revision: https://reviews.llvm.org/D48202 llvm-svn: 335183
2018-06-21 06:01:04 +08:00
; CHECK: entry:
; CHECK-NOT: br label %
trap: ; preds = %0, %entry
tail call void @llvm.trap() noreturn nounwind
unreachable
T:
; CHECK: ret i32 4
ret i32 4
}
; CHECK-LABEL: @test_objectsize_null_flag(
define i64 @test_objectsize_null_flag(i8* %ptr) {
entry:
; CHECK: ret i64 -1
%0 = tail call i64 @llvm.objectsize.i64(i8* null, i1 false, i1 true)
ret i64 %0
}
; CHECK-LABEL: @test_objectsize_null_flag_min(
define i64 @test_objectsize_null_flag_min(i8* %ptr) {
entry:
; CHECK: ret i64 0
%0 = tail call i64 @llvm.objectsize.i64(i8* null, i1 true, i1 true)
ret i64 %0
}
; Test foldable null pointers because we evaluate them with non-exact modes in
; CodeGenPrepare.
; CHECK-LABEL: @test_objectsize_null_flag_noas0(
define i64 @test_objectsize_null_flag_noas0() {
entry:
; CHECK: ret i64 -1
%0 = tail call i64 @llvm.objectsize.i64.p1i8(i8 addrspace(1)* null, i1 false,
i1 true)
ret i64 %0
}
; CHECK-LABEL: @test_objectsize_null_flag_min_noas0(
define i64 @test_objectsize_null_flag_min_noas0() {
entry:
; CHECK: ret i64 0
%0 = tail call i64 @llvm.objectsize.i64.p1i8(i8 addrspace(1)* null, i1 true,
i1 true)
ret i64 %0
}
; CHECK-LABEL: @test_objectsize_null_known_flag_noas0
define i64 @test_objectsize_null_known_flag_noas0() {
entry:
; CHECK: ret i64 -1
%0 = tail call i64 @llvm.objectsize.i64.p1i8(i8 addrspace(1)* null, i1 false,
i1 false)
ret i64 %0
}
; CHECK-LABEL: @test_objectsize_null_known_flag_min_noas0
define i64 @test_objectsize_null_known_flag_min_noas0() {
entry:
; CHECK: ret i64 0
%0 = tail call i64 @llvm.objectsize.i64.p1i8(i8 addrspace(1)* null, i1 true,
i1 false)
ret i64 %0
}
declare i64 @llvm.objectsize.i64(i8*, i1, i1) nounwind readonly
declare i64 @llvm.objectsize.i64.p1i8(i8 addrspace(1)*, i1, i1) nounwind readonly
declare void @llvm.trap() nounwind