maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/llvm/test/CodeGen/AArch64/arm64-jumptable.ll

35 lines
882 B
LLVM
Raw Normal View History

ARM64: initial backend import This adds a second implementation of the AArch64 architecture to LLVM, accessible in parallel via the "arm64" triple. The plan over the coming weeks & months is to merge the two into a single backend, during which time thorough code review should naturally occur. Everything will be easier with the target in-tree though, hence this commit. llvm-svn: 205090
2014-03-29 18:18:08 +08:00
; RUN: llc -mtriple=arm64-apple-ios < %s | FileCheck %s
; RUN: llc -mtriple=arm64-linux-gnu < %s | FileCheck %s --check-prefix=CHECK-LINUX
; <rdar://11417675>
[SimplifyCFG] Handle tail-sinking of more than 2 incoming branches This was a real restriction in the original version of SinkIfThenCodeToEnd. Now it's been rewritten, the restriction can be lifted. As part of this, we handle a very common and useful case where one of the incoming branches is actually conditional. Consider: if (a) x(1); else if (b) x(2); This produces the following CFG: [if] / \ [x(1)] [if] | | \ | | \ | [x(2)] | \ | / [ end ] [end] has two unconditional predecessor arcs and one conditional. The conditional refers to the implicit empty 'else' arc. This same pattern can also be caused by an empty default block in a switch. We can't sink the call to x() down to end because no call to x() happens on the third incoming arc (assume that x() has sideeffects for the sake of argument; if something is safe to speculate we could indeed sink nevertheless but this cannot happen in the general case and causes many extra selects). We are now able to detect this case and split off the unconditional arcs to a common successor: [if] / \ [x(1)] [if] | | \ | | \ | [x(2)] | \ / | [sink.split] | \ / [ end ] Now we can sink the call to x() into %sink.split. This can cause significant code simplification in many testcases. llvm-svn: 280364
2016-09-01 20:58:13 +08:00
define void @sum(i32 %a, i32* %to, i32 %c) {
ARM64: initial backend import This adds a second implementation of the AArch64 architecture to LLVM, accessible in parallel via the "arm64" triple. The plan over the coming weeks & months is to merge the two into a single backend, during which time thorough code review should naturally occur. Everything will be easier with the target in-tree though, hence this commit. llvm-svn: 205090
2014-03-29 18:18:08 +08:00
entry:
[SimplifyCFG] Handle tail-sinking of more than 2 incoming branches This was a real restriction in the original version of SinkIfThenCodeToEnd. Now it's been rewritten, the restriction can be lifted. As part of this, we handle a very common and useful case where one of the incoming branches is actually conditional. Consider: if (a) x(1); else if (b) x(2); This produces the following CFG: [if] / \ [x(1)] [if] | | \ | | \ | [x(2)] | \ | / [ end ] [end] has two unconditional predecessor arcs and one conditional. The conditional refers to the implicit empty 'else' arc. This same pattern can also be caused by an empty default block in a switch. We can't sink the call to x() down to end because no call to x() happens on the third incoming arc (assume that x() has sideeffects for the sake of argument; if something is safe to speculate we could indeed sink nevertheless but this cannot happen in the general case and causes many extra selects). We are now able to detect this case and split off the unconditional arcs to a common successor: [if] / \ [x(1)] [if] | | \ | | \ | [x(2)] | \ / | [sink.split] | \ / [ end ] Now we can sink the call to x() into %sink.split. This can cause significant code simplification in many testcases. llvm-svn: 280364
2016-09-01 20:58:13 +08:00
switch i32 %a, label %exit [
ARM64: initial backend import This adds a second implementation of the AArch64 architecture to LLVM, accessible in parallel via the "arm64" triple. The plan over the coming weeks & months is to merge the two into a single backend, during which time thorough code review should naturally occur. Everything will be easier with the target in-tree though, hence this commit. llvm-svn: 205090
2014-03-29 18:18:08 +08:00
i32 1, label %bb1
[SimplifyCFG] Avoid quadratic on a predecessors number behavior in instruction sinking. If a block has N predecessors, then the current algorithm will try to sink common code to this block N times (whenever we visit a predecessor). Every attempt to sink the common code includes going through all predecessors, so the complexity of the algorithm becomes O(N^2). With this patch we try to sink common code only when we visit the block itself. With this, the complexity goes down to O(N). As a side effect, the moment the code is sunk is slightly different than before (the order of simplifications has been changed), that's why I had to adjust two tests (note that neither of the tests is supposed to test SimplifyCFG): * test/CodeGen/AArch64/arm64-jumptable.ll - changes in this test mimic the changes that previous implementation of SimplifyCFG would do. * test/CodeGen/ARM/avoid-cpsr-rmw.ll - in this test I disabled common code sinking by a command line flag. llvm-svn: 321236
2017-12-21 09:22:13 +08:00
i32 2, label %exit.sink.split
ARM64: initial backend import This adds a second implementation of the AArch64 architecture to LLVM, accessible in parallel via the "arm64" triple. The plan over the coming weeks & months is to merge the two into a single backend, during which time thorough code review should naturally occur. Everything will be easier with the target in-tree though, hence this commit. llvm-svn: 205090
2014-03-29 18:18:08 +08:00
i32 3, label %bb3
i32 4, label %bb4
]
bb1:
[SimplifyCFG] Handle tail-sinking of more than 2 incoming branches This was a real restriction in the original version of SinkIfThenCodeToEnd. Now it's been rewritten, the restriction can be lifted. As part of this, we handle a very common and useful case where one of the incoming branches is actually conditional. Consider: if (a) x(1); else if (b) x(2); This produces the following CFG: [if] / \ [x(1)] [if] | | \ | | \ | [x(2)] | \ | / [ end ] [end] has two unconditional predecessor arcs and one conditional. The conditional refers to the implicit empty 'else' arc. This same pattern can also be caused by an empty default block in a switch. We can't sink the call to x() down to end because no call to x() happens on the third incoming arc (assume that x() has sideeffects for the sake of argument; if something is safe to speculate we could indeed sink nevertheless but this cannot happen in the general case and causes many extra selects). We are now able to detect this case and split off the unconditional arcs to a common successor: [if] / \ [x(1)] [if] | | \ | | \ | [x(2)] | \ / | [sink.split] | \ / [ end ] Now we can sink the call to x() into %sink.split. This can cause significant code simplification in many testcases. llvm-svn: 280364
2016-09-01 20:58:13 +08:00
%b = add i32 %c, 1
[SimplifyCFG] Avoid quadratic on a predecessors number behavior in instruction sinking. If a block has N predecessors, then the current algorithm will try to sink common code to this block N times (whenever we visit a predecessor). Every attempt to sink the common code includes going through all predecessors, so the complexity of the algorithm becomes O(N^2). With this patch we try to sink common code only when we visit the block itself. With this, the complexity goes down to O(N). As a side effect, the moment the code is sunk is slightly different than before (the order of simplifications has been changed), that's why I had to adjust two tests (note that neither of the tests is supposed to test SimplifyCFG): * test/CodeGen/AArch64/arm64-jumptable.ll - changes in this test mimic the changes that previous implementation of SimplifyCFG would do. * test/CodeGen/ARM/avoid-cpsr-rmw.ll - in this test I disabled common code sinking by a command line flag. llvm-svn: 321236
2017-12-21 09:22:13 +08:00
br label %exit.sink.split
ARM64: initial backend import This adds a second implementation of the AArch64 architecture to LLVM, accessible in parallel via the "arm64" triple. The plan over the coming weeks & months is to merge the two into a single backend, during which time thorough code review should naturally occur. Everything will be easier with the target in-tree though, hence this commit. llvm-svn: 205090
2014-03-29 18:18:08 +08:00
bb3:
[SimplifyCFG] Avoid quadratic on a predecessors number behavior in instruction sinking. If a block has N predecessors, then the current algorithm will try to sink common code to this block N times (whenever we visit a predecessor). Every attempt to sink the common code includes going through all predecessors, so the complexity of the algorithm becomes O(N^2). With this patch we try to sink common code only when we visit the block itself. With this, the complexity goes down to O(N). As a side effect, the moment the code is sunk is slightly different than before (the order of simplifications has been changed), that's why I had to adjust two tests (note that neither of the tests is supposed to test SimplifyCFG): * test/CodeGen/AArch64/arm64-jumptable.ll - changes in this test mimic the changes that previous implementation of SimplifyCFG would do. * test/CodeGen/ARM/avoid-cpsr-rmw.ll - in this test I disabled common code sinking by a command line flag. llvm-svn: 321236
2017-12-21 09:22:13 +08:00
br label %exit.sink.split
ARM64: initial backend import This adds a second implementation of the AArch64 architecture to LLVM, accessible in parallel via the "arm64" triple. The plan over the coming weeks & months is to merge the two into a single backend, during which time thorough code review should naturally occur. Everything will be easier with the target in-tree though, hence this commit. llvm-svn: 205090
2014-03-29 18:18:08 +08:00
bb4:
[SimplifyCFG] Avoid quadratic on a predecessors number behavior in instruction sinking. If a block has N predecessors, then the current algorithm will try to sink common code to this block N times (whenever we visit a predecessor). Every attempt to sink the common code includes going through all predecessors, so the complexity of the algorithm becomes O(N^2). With this patch we try to sink common code only when we visit the block itself. With this, the complexity goes down to O(N). As a side effect, the moment the code is sunk is slightly different than before (the order of simplifications has been changed), that's why I had to adjust two tests (note that neither of the tests is supposed to test SimplifyCFG): * test/CodeGen/AArch64/arm64-jumptable.ll - changes in this test mimic the changes that previous implementation of SimplifyCFG would do. * test/CodeGen/ARM/avoid-cpsr-rmw.ll - in this test I disabled common code sinking by a command line flag. llvm-svn: 321236
2017-12-21 09:22:13 +08:00
br label %exit.sink.split
exit.sink.split:
%.sink = phi i32 [ 5, %bb4 ], [ %b, %bb1 ], [ 3, %bb3 ], [ %a, %entry ]
store i32 %.sink, i32* %to
ARM64: initial backend import This adds a second implementation of the AArch64 architecture to LLVM, accessible in parallel via the "arm64" triple. The plan over the coming weeks & months is to merge the two into a single backend, during which time thorough code review should naturally occur. Everything will be easier with the target in-tree though, hence this commit. llvm-svn: 205090
2014-03-29 18:18:08 +08:00
br label %exit
exit:
ret void
}
; CHECK-LABEL: sum:
; CHECK: adrp {{x[0-9]+}}, LJTI0_0@PAGE
; CHECK: add {{x[0-9]+}}, {{x[0-9]+}}, LJTI0_0@PAGEOFF
; CHECK-LINUX-LABEL: sum:
; CHECK-LINUX: adrp {{x[0-9]+}}, .LJTI0_0
; CHECK-LINUX: add {{x[0-9]+}}, {{x[0-9]+}}, :lo12:.LJTI0_0