| ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py |
| ; RUN: opt < %s -S -unroll-runtime -unroll-count=2 -loop-unroll -unroll-runtime-epilog=true | FileCheck %s -check-prefix=EPILOG |
| ; RUN: opt < %s -S -unroll-runtime -unroll-count=2 -loop-unroll -unroll-runtime-epilog=false | FileCheck %s -check-prefix=PROLOG |
| target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" |
| |
| ; This test case documents how runtime loop unrolling handles the case |
| ; when the backedge-count is -1. |
| |
| ; If %N, the backedge-taken count, is -1 then %0 unsigned-overflows |
| ; and is 0. %xtraiter too is 0, signifying that the total trip-count |
| ; is divisible by 2. The prologue then branches to the unrolled loop |
| ; and executes the 2^32 iterations there, in groups of 2. |
| |
| define i32 @foo(i32 %N) { |
| ; EPILOG-LABEL: @foo( |
| ; EPILOG-NEXT: entry: |
| ; EPILOG-NEXT: [[TMP0:%.*]] = add i32 [[N:%.*]], 1 |
| ; EPILOG-NEXT: [[XTRAITER:%.*]] = and i32 [[TMP0]], 1 |
| ; EPILOG-NEXT: [[TMP1:%.*]] = icmp ult i32 [[N]], 1 |
| ; EPILOG-NEXT: br i1 [[TMP1]], label [[WHILE_END_UNR_LCSSA:%.*]], label [[ENTRY_NEW:%.*]] |
| ; EPILOG: entry.new: |
| ; EPILOG-NEXT: [[UNROLL_ITER:%.*]] = sub i32 [[TMP0]], [[XTRAITER]] |
| ; EPILOG-NEXT: br label [[WHILE_BODY:%.*]] |
| ; EPILOG: while.body: |
| ; EPILOG-NEXT: [[I:%.*]] = phi i32 [ 0, [[ENTRY_NEW]] ], [ [[INC_1:%.*]], [[WHILE_BODY]] ] |
| ; EPILOG-NEXT: [[NITER:%.*]] = phi i32 [ 0, [[ENTRY_NEW]] ], [ [[NITER_NEXT_1:%.*]], [[WHILE_BODY]] ] |
| ; EPILOG-NEXT: [[INC:%.*]] = add nuw nsw i32 [[I]], 1 |
| ; EPILOG-NEXT: [[NITER_NEXT:%.*]] = add nuw nsw i32 [[NITER]], 1 |
| ; EPILOG-NEXT: [[INC_1]] = add i32 [[INC]], 1 |
| ; EPILOG-NEXT: [[NITER_NEXT_1]] = add i32 [[NITER_NEXT]], 1 |
| ; EPILOG-NEXT: [[NITER_NCMP_1:%.*]] = icmp eq i32 [[NITER_NEXT_1]], [[UNROLL_ITER]] |
| ; EPILOG-NEXT: br i1 [[NITER_NCMP_1]], label [[WHILE_END_UNR_LCSSA_LOOPEXIT:%.*]], label [[WHILE_BODY]], !llvm.loop [[LOOP0:![0-9]+]] |
| ; EPILOG: while.end.unr-lcssa.loopexit: |
| ; EPILOG-NEXT: [[I_LCSSA_PH_PH:%.*]] = phi i32 [ [[INC]], [[WHILE_BODY]] ] |
| ; EPILOG-NEXT: [[I_UNR_PH:%.*]] = phi i32 [ [[INC_1]], [[WHILE_BODY]] ] |
| ; EPILOG-NEXT: br label [[WHILE_END_UNR_LCSSA]] |
| ; EPILOG: while.end.unr-lcssa: |
| ; EPILOG-NEXT: [[I_LCSSA_PH:%.*]] = phi i32 [ undef, [[ENTRY:%.*]] ], [ [[I_LCSSA_PH_PH]], [[WHILE_END_UNR_LCSSA_LOOPEXIT]] ] |
| ; EPILOG-NEXT: [[I_UNR:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[I_UNR_PH]], [[WHILE_END_UNR_LCSSA_LOOPEXIT]] ] |
| ; EPILOG-NEXT: [[LCMP_MOD:%.*]] = icmp ne i32 [[XTRAITER]], 0 |
| ; EPILOG-NEXT: br i1 [[LCMP_MOD]], label [[WHILE_BODY_EPIL_PREHEADER:%.*]], label [[WHILE_END:%.*]] |
| ; EPILOG: while.body.epil.preheader: |
| ; EPILOG-NEXT: br label [[WHILE_BODY_EPIL:%.*]] |
| ; EPILOG: while.body.epil: |
| ; EPILOG-NEXT: br label [[WHILE_END]] |
| ; EPILOG: while.end: |
| ; EPILOG-NEXT: [[I_LCSSA:%.*]] = phi i32 [ [[I_LCSSA_PH]], [[WHILE_END_UNR_LCSSA]] ], [ [[I_UNR]], [[WHILE_BODY_EPIL]] ] |
| ; EPILOG-NEXT: ret i32 [[I_LCSSA]] |
| ; |
| ; PROLOG-LABEL: @foo( |
| ; PROLOG-NEXT: entry: |
| ; PROLOG-NEXT: [[TMP0:%.*]] = add i32 [[N:%.*]], 1 |
| ; PROLOG-NEXT: [[XTRAITER:%.*]] = and i32 [[TMP0]], 1 |
| ; PROLOG-NEXT: [[LCMP_MOD:%.*]] = icmp ne i32 [[XTRAITER]], 0 |
| ; PROLOG-NEXT: br i1 [[LCMP_MOD]], label [[WHILE_BODY_PROL_PREHEADER:%.*]], label [[WHILE_BODY_PROL_LOOPEXIT:%.*]] |
| ; PROLOG: while.body.prol.preheader: |
| ; PROLOG-NEXT: br label [[WHILE_BODY_PROL:%.*]] |
| ; PROLOG: while.body.prol: |
| ; PROLOG-NEXT: br label [[WHILE_BODY_PROL_LOOPEXIT]] |
| ; PROLOG: while.body.prol.loopexit: |
| ; PROLOG-NEXT: [[I_LCSSA_UNR:%.*]] = phi i32 [ undef, [[ENTRY:%.*]] ], [ 0, [[WHILE_BODY_PROL]] ] |
| ; PROLOG-NEXT: [[I_UNR:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ 1, [[WHILE_BODY_PROL]] ] |
| ; PROLOG-NEXT: [[TMP1:%.*]] = icmp ult i32 [[N]], 1 |
| ; PROLOG-NEXT: br i1 [[TMP1]], label [[WHILE_END:%.*]], label [[ENTRY_NEW:%.*]] |
| ; PROLOG: entry.new: |
| ; PROLOG-NEXT: br label [[WHILE_BODY:%.*]] |
| ; PROLOG: while.body: |
| ; PROLOG-NEXT: [[I:%.*]] = phi i32 [ [[I_UNR]], [[ENTRY_NEW]] ], [ [[INC_1:%.*]], [[WHILE_BODY]] ] |
| ; PROLOG-NEXT: [[INC:%.*]] = add i32 [[I]], 1 |
| ; PROLOG-NEXT: [[CMP_1:%.*]] = icmp eq i32 [[INC]], [[N]] |
| ; PROLOG-NEXT: [[INC_1]] = add i32 [[INC]], 1 |
| ; PROLOG-NEXT: br i1 [[CMP_1]], label [[WHILE_END_UNR_LCSSA:%.*]], label [[WHILE_BODY]], !llvm.loop [[LOOP0:![0-9]+]] |
| ; PROLOG: while.end.unr-lcssa: |
| ; PROLOG-NEXT: [[I_LCSSA_PH:%.*]] = phi i32 [ [[INC]], [[WHILE_BODY]] ] |
| ; PROLOG-NEXT: br label [[WHILE_END]] |
| ; PROLOG: while.end: |
| ; PROLOG-NEXT: [[I_LCSSA:%.*]] = phi i32 [ [[I_LCSSA_UNR]], [[WHILE_BODY_PROL_LOOPEXIT]] ], [ [[I_LCSSA_PH]], [[WHILE_END_UNR_LCSSA]] ] |
| ; PROLOG-NEXT: ret i32 [[I_LCSSA]] |
| ; |
| entry: |
| br label %while.body |
| |
| while.body: ; preds = %while.body, %entry |
| %i = phi i32 [ 0, %entry ], [ %inc, %while.body ] |
| %cmp = icmp eq i32 %i, %N |
| %inc = add i32 %i, 1 |
| br i1 %cmp, label %while.end, label %while.body |
| |
| while.end: ; preds = %while.body |
| ret i32 %i |
| } |