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llvm-project/llvm/test/CodeGen/AArch64/fast-isel-tail-call.ll

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[CodeGen] Pass SDAG an ORE, and replace FastISel stats with remarks. In the long-term, we want to replace statistics with something finer-grained that lets us gather per-function data. Remarks are that replacement. Create an ORE instance in SelectionDAGISel, and pass it to SelectionDAG. SelectionDAG was used so that we can emit remarks from all SelectionDAG-related code, including TargetLowering and DAGCombiner. This isn't used in the current patch but Adam tells me he's interested for the fp-contract combines. Use the ORE instance to emit FastISel failures as remarks (instead of the mix of dbgs() dumps and statistics that we currently have). Eventually, we want to have an API that tells us whether remarks are enabled (http://llvm.org/PR32352) so that we don't emit expensive remarks (in this case, dumping IR) when it's not needed. For now, use 'isEnabled' as a crude replacement. This does mean that the replacement for '-fast-isel-verbose' is now '-pass-remarks-missed=isel'. Additionally, clang users also need to enable remark diagnostics, using '-Rpass-missed=isel'. This also removes '-fast-isel-verbose2': there are no static statistics that we want to only enable in asserts builds, so we can always use the remarks regardless of the build type. Differential Revision: https://reviews.llvm.org/D31405 llvm-svn: 299093
2017-03-31 01:49:58 +08:00
; RUN: llc -fast-isel -pass-remarks-missed=isel -pass-remarks-missed=isel \
; RUN: -mtriple arm64-- < %s 2> %t | FileCheck %s
[CodeGen] Remove dead FastISel code after SDAG emitted a tailcall. When SDAGISel (top-down) selects a tail-call, it skips the remainder of the block. If, before that, FastISel (bottom-up) selected some of the (no-op) next few instructions, we can end up with dead instructions following the terminator (selected by SDAGISel). We need to erase them, as we know they aren't necessary (in addition to being incorrect). We already do this when FastISel falls back on the tail-call itself. Also remove the FastISel-emitted code if we fallback on the instructions between the tail-call and the return. llvm-svn: 296552
2017-03-01 08:43:42 +08:00
; RUN: cat %t | FileCheck %s --check-prefix MISSED
%struct = type { [4 x i32] }
declare %struct @external()
; Check that, when fastisel falls back to SDAG, we don't emit instructions
; that follow a tail-call and would have been dropped by pure SDAGISel.
; Here, the %struct extractvalue should fail FastISel.
[CodeGen] Pass SDAG an ORE, and replace FastISel stats with remarks. In the long-term, we want to replace statistics with something finer-grained that lets us gather per-function data. Remarks are that replacement. Create an ORE instance in SelectionDAGISel, and pass it to SelectionDAG. SelectionDAG was used so that we can emit remarks from all SelectionDAG-related code, including TargetLowering and DAGCombiner. This isn't used in the current patch but Adam tells me he's interested for the fp-contract combines. Use the ORE instance to emit FastISel failures as remarks (instead of the mix of dbgs() dumps and statistics that we currently have). Eventually, we want to have an API that tells us whether remarks are enabled (http://llvm.org/PR32352) so that we don't emit expensive remarks (in this case, dumping IR) when it's not needed. For now, use 'isEnabled' as a crude replacement. This does mean that the replacement for '-fast-isel-verbose' is now '-pass-remarks-missed=isel'. Additionally, clang users also need to enable remark diagnostics, using '-Rpass-missed=isel'. This also removes '-fast-isel-verbose2': there are no static statistics that we want to only enable in asserts builds, so we can always use the remarks regardless of the build type. Differential Revision: https://reviews.llvm.org/D31405 llvm-svn: 299093
2017-03-31 01:49:58 +08:00
; MISSED: FastISel missed: %tmp1 = extractvalue %struct %tmp0, 0
[CodeGen] Remove dead FastISel code after SDAG emitted a tailcall. When SDAGISel (top-down) selects a tail-call, it skips the remainder of the block. If, before that, FastISel (bottom-up) selected some of the (no-op) next few instructions, we can end up with dead instructions following the terminator (selected by SDAGISel). We need to erase them, as we know they aren't necessary (in addition to being incorrect). We already do this when FastISel falls back on the tail-call itself. Also remove the FastISel-emitted code if we fallback on the instructions between the tail-call and the return. llvm-svn: 296552
2017-03-01 08:43:42 +08:00
; CHECK-LABEL: test:
; CHECK: b external
; CHECK-NEXT: .Lfunc_end0:
define i32 @test() nounwind {
%tmp0 = tail call %struct @external()
%tmp1 = extractvalue %struct %tmp0, 0
%tmp2 = extractvalue [4 x i32] %tmp1, 0
ret i32 %tmp2
}