Florian Hahn 2d60f87111
[VPlan] Only use legacy cost for instructions only used by exit conds. (#174029)
Currently we need to precompute costs for exit conditions, to match the
legacy cost, as they will get replaced by a compare against the
canonical IV (or others, like active-lane-mask or EVL based) and the
original compare will get removed.

This is not true for instructions with users other than the exit
condition. Those will remain, and we can just use the VPlan-based cost
model to get more accurate results.

This improves results in some cases, like
@test_value_in_exit_compare_chain_used_outside because the IV increment
user outside the loop is replaced by computing the final value outside
the loop.

It also fixes a crash introduced by f196b1d66ff (#146525).

PR: https://github.com/llvm/llvm-project/pull/174029
2025-12-31 13:34:54 +00:00

194 lines
11 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
; RUN: opt -p loop-vectorize -mtriple=x86_64-apple-macosx -mcpu=penryn -S %s | FileCheck %s
define i64 @test_value_in_exit_compare_chain_used_outside(ptr %src, i64 %x, i64 range(i64 1, 32) %N) {
; CHECK-LABEL: define i64 @test_value_in_exit_compare_chain_used_outside(
; CHECK-SAME: ptr [[SRC:%.*]], i64 [[X:%.*]], i64 range(i64 1, 32) [[N:%.*]]) #[[ATTR0:[0-9]+]] {
; CHECK-NEXT: [[ENTRY:.*]]:
; CHECK-NEXT: [[TMP0:%.*]] = add nsw i64 [[N]], -1
; CHECK-NEXT: [[TMP1:%.*]] = freeze i64 [[TMP0]]
; CHECK-NEXT: [[UMIN2:%.*]] = call i64 @llvm.umin.i64(i64 [[TMP1]], i64 [[X]])
; CHECK-NEXT: [[TMP2:%.*]] = add nuw nsw i64 [[UMIN2]], 1
; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ule i64 [[TMP2]], 8
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label %[[SCALAR_PH:.*]], label %[[VECTOR_SCEVCHECK:.*]]
; CHECK: [[VECTOR_SCEVCHECK]]:
; CHECK-NEXT: [[TMP3:%.*]] = add nsw i64 [[N]], -1
; CHECK-NEXT: [[TMP4:%.*]] = freeze i64 [[TMP3]]
; CHECK-NEXT: [[UMIN:%.*]] = call i64 @llvm.umin.i64(i64 [[TMP4]], i64 [[X]])
; CHECK-NEXT: [[TMP5:%.*]] = trunc i64 [[UMIN]] to i1
; CHECK-NEXT: [[TMP6:%.*]] = icmp ugt i64 [[UMIN]], 1
; CHECK-NEXT: [[TMP7:%.*]] = or i1 [[TMP5]], [[TMP6]]
; CHECK-NEXT: br i1 [[TMP7]], label %[[SCALAR_PH]], label %[[VECTOR_PH:.*]]
; CHECK: [[VECTOR_PH]]:
; CHECK-NEXT: [[N_MOD_VF:%.*]] = urem i64 [[TMP2]], 8
; CHECK-NEXT: [[TMP8:%.*]] = icmp eq i64 [[N_MOD_VF]], 0
; CHECK-NEXT: [[TMP9:%.*]] = select i1 [[TMP8]], i64 8, i64 [[N_MOD_VF]]
; CHECK-NEXT: [[N_VEC:%.*]] = sub i64 [[TMP2]], [[TMP9]]
; CHECK-NEXT: br label %[[VECTOR_BODY:.*]]
; CHECK: [[VECTOR_BODY]]:
; CHECK-NEXT: [[TMP10:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_PHI:%.*]] = phi <4 x i8> [ zeroinitializer, %[[VECTOR_PH]] ], [ [[TMP16:%.*]], %[[VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_PHI3:%.*]] = phi <4 x i8> [ zeroinitializer, %[[VECTOR_PH]] ], [ [[TMP17:%.*]], %[[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP18:%.*]] = and i64 [[TMP10]], 1
; CHECK-NEXT: [[TMP26:%.*]] = getelementptr i8, ptr [[SRC]], i64 [[TMP18]]
; CHECK-NEXT: [[TMP12:%.*]] = getelementptr i8, ptr [[TMP26]], i64 0
; CHECK-NEXT: [[TMP13:%.*]] = getelementptr i8, ptr [[TMP12]], i64 -3
; CHECK-NEXT: [[TMP14:%.*]] = getelementptr i8, ptr [[TMP26]], i64 -4
; CHECK-NEXT: [[TMP15:%.*]] = getelementptr i8, ptr [[TMP14]], i64 -3
; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <4 x i8>, ptr [[TMP13]], align 1
; CHECK-NEXT: [[WIDE_LOAD4:%.*]] = load <4 x i8>, ptr [[TMP15]], align 1
; CHECK-NEXT: [[REVERSE:%.*]] = shufflevector <4 x i8> [[WIDE_LOAD]], <4 x i8> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
; CHECK-NEXT: [[REVERSE5:%.*]] = shufflevector <4 x i8> [[WIDE_LOAD4]], <4 x i8> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
; CHECK-NEXT: [[TMP16]] = xor <4 x i8> [[REVERSE]], [[VEC_PHI]]
; CHECK-NEXT: [[TMP17]] = xor <4 x i8> [[REVERSE5]], [[VEC_PHI3]]
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[TMP10]], 8
; CHECK-NEXT: [[TMP30:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
; CHECK-NEXT: br i1 [[TMP30]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
; CHECK: [[MIDDLE_BLOCK]]:
; CHECK-NEXT: [[BIN_RDX:%.*]] = xor <4 x i8> [[TMP17]], [[TMP16]]
; CHECK-NEXT: [[TMP19:%.*]] = call i8 @llvm.vector.reduce.xor.v4i8(<4 x i8> [[BIN_RDX]])
; CHECK-NEXT: br label %[[SCALAR_PH]]
; CHECK: [[SCALAR_PH]]:
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], %[[MIDDLE_BLOCK]] ], [ 0, %[[ENTRY]] ], [ 0, %[[VECTOR_SCEVCHECK]] ]
; CHECK-NEXT: [[BC_MERGE_RDX:%.*]] = phi i8 [ [[TMP19]], %[[MIDDLE_BLOCK]] ], [ 0, %[[ENTRY]] ], [ 0, %[[VECTOR_SCEVCHECK]] ]
; CHECK-NEXT: br label %[[LOOP_HEADER:.*]]
; CHECK: [[LOOP_HEADER]]:
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], %[[SCALAR_PH]] ], [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ]
; CHECK-NEXT: [[XOR_RED:%.*]] = phi i8 [ [[BC_MERGE_RDX]], %[[SCALAR_PH]] ], [ [[XOR_RED_NEXT:%.*]], %[[LOOP_LATCH]] ]
; CHECK-NEXT: [[IV_AND:%.*]] = and i64 [[IV]], 1
; CHECK-NEXT: [[X_INC:%.*]] = add i64 [[IV_AND]], [[X]]
; CHECK-NEXT: [[GEP_SRC:%.*]] = getelementptr i8, ptr [[SRC]], i64 [[IV_AND]]
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i64 [[X_INC]], 0
; CHECK-NEXT: br i1 [[CMP]], label %[[EXIT_1:.*]], label %[[LOOP_LATCH]]
; CHECK: [[LOOP_LATCH]]:
; CHECK-NEXT: [[L:%.*]] = load i8, ptr [[GEP_SRC]], align 1
; CHECK-NEXT: [[XOR_RED_NEXT]] = xor i8 [[L]], [[XOR_RED]]
; CHECK-NEXT: [[IV_NEXT]] = add i64 [[IV]], 1
; CHECK-NEXT: [[EC:%.*]] = icmp eq i64 [[IV_NEXT]], [[N]]
; CHECK-NEXT: br i1 [[EC]], label %[[EXIT_2:.*]], label %[[LOOP_HEADER]], !llvm.loop [[LOOP3:![0-9]+]]
; CHECK: [[EXIT_1]]:
; CHECK-NEXT: [[X_INC_LCSSA:%.*]] = phi i64 [ [[X_INC]], %[[LOOP_HEADER]] ]
; CHECK-NEXT: ret i64 [[X_INC_LCSSA]]
; CHECK: [[EXIT_2]]:
; CHECK-NEXT: [[XOR_RED_NEXT_LCSSA:%.*]] = phi i8 [ [[XOR_RED_NEXT]], %[[LOOP_LATCH]] ]
; CHECK-NEXT: [[R:%.*]] = zext i8 [[XOR_RED_NEXT_LCSSA]] to i64
; CHECK-NEXT: ret i64 [[R]]
;
entry:
br label %loop.header
loop.header:
%iv = phi i64 [ 0, %entry ], [ %iv.next, %loop.latch ]
%xor.red = phi i8 [ 0, %entry ], [ %xor.red.next, %loop.latch ]
%iv.and = and i64 %iv, 1
%x.inc = add i64 %iv.and, %x
%gep.src = getelementptr i8, ptr %src, i64 %iv.and
%cmp = icmp eq i64 %x.inc, 0
br i1 %cmp, label %exit.1, label %loop.latch
loop.latch:
%l = load i8, ptr %gep.src, align 1
%xor.red.next = xor i8 %l, %xor.red
%iv.next = add i64 %iv, 1
%ec = icmp eq i64 %iv.next, %N
br i1 %ec, label %exit.2, label %loop.header
exit.1:
ret i64 %x.inc
exit.2:
%r = zext i8 %xor.red.next to i64
ret i64 %r
}
@gg = constant [80 x i8] c"22 "
define i1 @test_exit_compare_other_users() #0 {
; CHECK-LABEL: define i1 @test_exit_compare_other_users(
; CHECK-SAME: ) #[[ATTR1:[0-9]+]] {
; CHECK-NEXT: [[ITER_CHECK:.*]]:
; CHECK-NEXT: br i1 false, label %[[VEC_EPILOG_SCALAR_PH:.*]], label %[[VECTOR_MAIN_LOOP_ITER_CHECK:.*]]
; CHECK: [[VECTOR_MAIN_LOOP_ITER_CHECK]]:
; CHECK-NEXT: br i1 false, label %[[VEC_EPILOG_PH:.*]], label %[[VECTOR_PH:.*]]
; CHECK: [[VECTOR_PH]]:
; CHECK-NEXT: br label %[[VECTOR_BODY:.*]]
; CHECK: [[VECTOR_BODY]]:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP0:%.*]] = sub i64 79, [[INDEX]]
; CHECK-NEXT: [[TMP1:%.*]] = getelementptr [1 x i8], ptr @gg, i64 [[TMP0]]
; CHECK-NEXT: [[TMP2:%.*]] = getelementptr i8, ptr [[TMP1]], i64 -24
; CHECK-NEXT: [[TMP3:%.*]] = getelementptr i8, ptr [[TMP2]], i64 -7
; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <8 x i8>, ptr [[TMP3]], align 1
; CHECK-NEXT: [[REVERSE:%.*]] = shufflevector <8 x i8> [[WIDE_LOAD]], <8 x i8> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
; CHECK-NEXT: [[TMP4:%.*]] = icmp eq <8 x i8> [[REVERSE]], splat (i8 32)
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 32
; CHECK-NEXT: [[TMP5:%.*]] = icmp eq i64 [[INDEX_NEXT]], 64
; CHECK-NEXT: br i1 [[TMP5]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP4:![0-9]+]]
; CHECK: [[MIDDLE_BLOCK]]:
; CHECK-NEXT: [[TMP6:%.*]] = extractelement <8 x i1> [[TMP4]], i32 7
; CHECK-NEXT: br i1 false, label %[[EXIT:.*]], label %[[VEC_EPILOG_ITER_CHECK:.*]]
; CHECK: [[VEC_EPILOG_ITER_CHECK]]:
; CHECK-NEXT: br i1 false, label %[[VEC_EPILOG_SCALAR_PH]], label %[[VEC_EPILOG_PH]], !prof [[PROF5:![0-9]+]]
; CHECK: [[VEC_EPILOG_PH]]:
; CHECK-NEXT: [[VEC_EPILOG_RESUME_VAL:%.*]] = phi i64 [ 64, %[[VEC_EPILOG_ITER_CHECK]] ], [ 0, %[[VECTOR_MAIN_LOOP_ITER_CHECK]] ]
; CHECK-NEXT: br label %[[VEC_EPILOG_VECTOR_BODY:.*]]
; CHECK: [[VEC_EPILOG_VECTOR_BODY]]:
; CHECK-NEXT: [[INDEX1:%.*]] = phi i64 [ [[VEC_EPILOG_RESUME_VAL]], %[[VEC_EPILOG_PH]] ], [ [[INDEX_NEXT4:%.*]], %[[VEC_EPILOG_VECTOR_BODY]] ]
; CHECK-NEXT: [[OFFSET_IDX:%.*]] = sub i64 79, [[INDEX1]]
; CHECK-NEXT: [[TMP7:%.*]] = getelementptr [1 x i8], ptr @gg, i64 [[OFFSET_IDX]]
; CHECK-NEXT: [[TMP8:%.*]] = getelementptr i8, ptr [[TMP7]], i64 0
; CHECK-NEXT: [[TMP9:%.*]] = getelementptr i8, ptr [[TMP8]], i64 -3
; CHECK-NEXT: [[WIDE_LOAD2:%.*]] = load <4 x i8>, ptr [[TMP9]], align 1
; CHECK-NEXT: [[REVERSE3:%.*]] = shufflevector <4 x i8> [[WIDE_LOAD2]], <4 x i8> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
; CHECK-NEXT: [[TMP10:%.*]] = icmp eq <4 x i8> [[REVERSE3]], splat (i8 32)
; CHECK-NEXT: [[INDEX_NEXT4]] = add nuw i64 [[INDEX1]], 4
; CHECK-NEXT: [[TMP11:%.*]] = icmp eq i64 [[INDEX_NEXT4]], 76
; CHECK-NEXT: br i1 [[TMP11]], label %[[VEC_EPILOG_MIDDLE_BLOCK:.*]], label %[[VEC_EPILOG_VECTOR_BODY]], !llvm.loop [[LOOP6:![0-9]+]]
; CHECK: [[VEC_EPILOG_MIDDLE_BLOCK]]:
; CHECK-NEXT: [[TMP12:%.*]] = extractelement <4 x i1> [[TMP10]], i32 3
; CHECK-NEXT: br i1 false, label %[[EXIT]], label %[[VEC_EPILOG_SCALAR_PH]]
; CHECK: [[VEC_EPILOG_SCALAR_PH]]:
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ 3, %[[VEC_EPILOG_MIDDLE_BLOCK]] ], [ 15, %[[VEC_EPILOG_ITER_CHECK]] ], [ 79, %[[ITER_CHECK]] ]
; CHECK-NEXT: br label %[[LOOP:.*]]
; CHECK: [[LOOP]]:
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], %[[VEC_EPILOG_SCALAR_PH]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
; CHECK-NEXT: [[IV_NEXT]] = add i64 [[IV]], -1
; CHECK-NEXT: [[BOUND_CHECK:%.*]] = icmp ne i64 [[IV]], 0
; CHECK-NEXT: [[GEP:%.*]] = getelementptr [1 x i8], ptr @gg, i64 [[IV]]
; CHECK-NEXT: [[LOAD:%.*]] = load i8, ptr [[GEP]], align 1
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[LOAD]], 32
; CHECK-NEXT: [[CONTINUE:%.*]] = and i1 [[CMP]], [[BOUND_CHECK]]
; CHECK-NEXT: br i1 [[CONTINUE]], label %[[LOOP]], label %[[EXIT]], !llvm.loop [[LOOP7:![0-9]+]]
; CHECK: [[EXIT]]:
; CHECK-NEXT: [[CMP_LCSSA:%.*]] = phi i1 [ [[CMP]], %[[LOOP]] ], [ [[TMP6]], %[[MIDDLE_BLOCK]] ], [ [[TMP12]], %[[VEC_EPILOG_MIDDLE_BLOCK]] ]
; CHECK-NEXT: ret i1 [[CMP_LCSSA]]
;
entry:
br label %loop
loop:
%iv = phi i64 [ 79, %entry ], [ %iv.next, %loop ]
%iv.next = add i64 %iv, -1
%bound.check = icmp ne i64 %iv, 0
%gep = getelementptr [1 x i8], ptr @gg, i64 %iv
%load = load i8, ptr %gep, align 1
%cmp = icmp eq i8 %load, 32
%continue = and i1 %cmp, %bound.check
br i1 %continue, label %loop, label %exit
exit:
ret i1 %cmp
}
attributes #0 = { "target-cpu"="znver3" }
;.
; CHECK: [[LOOP0]] = distinct !{[[LOOP0]], [[META1:![0-9]+]], [[META2:![0-9]+]]}
; CHECK: [[META1]] = !{!"llvm.loop.isvectorized", i32 1}
; CHECK: [[META2]] = !{!"llvm.loop.unroll.runtime.disable"}
; CHECK: [[LOOP3]] = distinct !{[[LOOP3]], [[META1]]}
; CHECK: [[LOOP4]] = distinct !{[[LOOP4]], [[META1]], [[META2]]}
; CHECK: [[PROF5]] = !{!"branch_weights", i32 4, i32 28}
; CHECK: [[LOOP6]] = distinct !{[[LOOP6]], [[META1]], [[META2]]}
; CHECK: [[LOOP7]] = distinct !{[[LOOP7]], [[META2]], [[META1]]}
;.