llvm-6502/test/CodeGen/Hexagon/remove_lsr.ll
Pranav Bhandarkar 4c3d3ecdf8 LLVM Bug Fix 13709: Remove needless lsr(Rp, #32) instruction access the
subreg_hireg of register pair Rp.

	* lib/Target/Hexagon/HexagonPeephole.cpp(PeepholeDoubleRegsMap): New
	 DenseMap similar to PeepholeMap that additionally records subreg info
	 too.
        (runOnMachineFunction): Record information in PeepholeDoubleRegsMap
        and copy propagate the high sub-reg of Rp0 in Rp1 = lsr(Rp0, #32) to
	the instruction Rx = COPY Rp1:logreg_subreg.
	* test/CodeGen/Hexagon/remove_lsr.ll: New test.
	



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163214 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-05 16:01:40 +00:00

81 lines
3.4 KiB
LLVM

; Test fix for PR-13709.
; RUN: llc -march=hexagon -mcpu=hexagonv4 < %s | FileCheck %s
; CHECK: foo
; CHECK-NOT: lsr(r{{[0-9]+}}:{{[0-9]+}}, #32)
; CHECK-NOT: lsr(r{{[0-9]+}}:{{[0-9]+}}, #32)
; Convert the sequence
; r17:16 = lsr(r11:10, #32)
; .. = r16
; into
; r17:16 = lsr(r11:10, #32)
; .. = r11
; This makes the lsr instruction dead and it gets removed subsequently
; by a dead code removal pass.
%union.vect64 = type { i64 }
%union.vect32 = type { i32 }
define void @foo(%union.vect64* nocapture %sss_extracted_bit_rx_data_ptr,
%union.vect32* nocapture %s_even, %union.vect32* nocapture %s_odd,
i8* nocapture %scr_s_even_code_ptr, i8* nocapture %scr_s_odd_code_ptr)
nounwind {
entry:
%scevgep = getelementptr %union.vect64* %sss_extracted_bit_rx_data_ptr, i32 1
%scevgep28 = getelementptr %union.vect32* %s_odd, i32 1
%scevgep32 = getelementptr %union.vect32* %s_even, i32 1
%scevgep36 = getelementptr i8* %scr_s_odd_code_ptr, i32 1
%scevgep39 = getelementptr i8* %scr_s_even_code_ptr, i32 1
br label %for.body
for.body: ; preds = %for.body, %entry
%lsr.iv42 = phi i32 [ %lsr.iv.next, %for.body ], [ 2, %entry ]
%lsr.iv40 = phi i8* [ %scevgep41, %for.body ], [ %scevgep39, %entry ]
%lsr.iv37 = phi i8* [ %scevgep38, %for.body ], [ %scevgep36, %entry ]
%lsr.iv33 = phi %union.vect32* [ %scevgep34, %for.body ], [ %scevgep32, %entry ]
%lsr.iv29 = phi %union.vect32* [ %scevgep30, %for.body ], [ %scevgep28, %entry ]
%lsr.iv = phi %union.vect64* [ %scevgep26, %for.body ], [ %scevgep, %entry ]
%predicate_1.023 = phi i8 [ undef, %entry ], [ %10, %for.body ]
%predicate.022 = phi i8 [ undef, %entry ], [ %9, %for.body ]
%val.021 = phi i64 [ undef, %entry ], [ %srcval, %for.body ]
%lsr.iv3335 = bitcast %union.vect32* %lsr.iv33 to i32*
%lsr.iv2931 = bitcast %union.vect32* %lsr.iv29 to i32*
%lsr.iv27 = bitcast %union.vect64* %lsr.iv to i64*
%0 = tail call i64 @llvm.hexagon.A2.vsubhs(i64 0, i64 %val.021)
%conv3 = sext i8 %predicate.022 to i32
%1 = trunc i64 %val.021 to i32
%2 = trunc i64 %0 to i32
%3 = tail call i32 @llvm.hexagon.C2.mux(i32 %conv3, i32 %1, i32 %2)
store i32 %3, i32* %lsr.iv3335, align 4, !tbaa !0
%conv8 = sext i8 %predicate_1.023 to i32
%4 = lshr i64 %val.021, 32
%5 = trunc i64 %4 to i32
%6 = lshr i64 %0, 32
%7 = trunc i64 %6 to i32
%8 = tail call i32 @llvm.hexagon.C2.mux(i32 %conv8, i32 %5, i32 %7)
store i32 %8, i32* %lsr.iv2931, align 4, !tbaa !0
%srcval = load i64* %lsr.iv27, align 8
%9 = load i8* %lsr.iv40, align 1, !tbaa !1
%10 = load i8* %lsr.iv37, align 1, !tbaa !1
%lftr.wideiv = trunc i32 %lsr.iv42 to i8
%exitcond = icmp eq i8 %lftr.wideiv, 32
%scevgep26 = getelementptr %union.vect64* %lsr.iv, i32 1
%scevgep30 = getelementptr %union.vect32* %lsr.iv29, i32 1
%scevgep34 = getelementptr %union.vect32* %lsr.iv33, i32 1
%scevgep38 = getelementptr i8* %lsr.iv37, i32 1
%scevgep41 = getelementptr i8* %lsr.iv40, i32 1
%lsr.iv.next = add i32 %lsr.iv42, 1
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body
ret void
}
declare i64 @llvm.hexagon.A2.vsubhs(i64, i64) nounwind readnone
declare i32 @llvm.hexagon.C2.mux(i32, i32, i32) nounwind readnone
!0 = metadata !{metadata !"long", metadata !1}
!1 = metadata !{metadata !"omnipotent char", metadata !2}
!2 = metadata !{metadata !"Simple C/C++ TBAA", null}