23c2f2e6b2
This patch marks the induction increment of the main induction variable of the vector loop as NUW when not folding the tail. If the tail is not folded, we know that End - Start >= Step (either statically or through the minimum iteration checks). We also know that both Start % Step == 0 and End % Step == 0. We exit the vector loop if %IV + %Step == %End. Hence we must exit the loop before %IV + %Step unsigned overflows and we can mark the induction increment as NUW. This should make SCEV return more precise bounds for the created vector loops, used by later optimizations, like late unrolling. At the moment quite a few tests still need to be updated, but before doing so I'd like to get initial feedback to make sure I am not missing anything. Note that this could probably be further improved by using information from the original IV. Attempt of modeling of the assumption in Alive2: https://alive2.llvm.org/ce/z/H_DL_g Part of a set of fixes required for PR50412. Reviewed By: mkazantsev Differential Revision: https://reviews.llvm.org/D103255
104 lines
4.5 KiB
LLVM
104 lines
4.5 KiB
LLVM
; REQUIRES: asserts
|
|
|
|
; RUN: opt -loop-vectorize -mtriple=arm64-apple-ios %s -S -debug -disable-output 2>&1 | FileCheck --check-prefix=CM %s
|
|
; RUN: opt -loop-vectorize -force-vector-width=2 -force-vector-interleave=1 %s -S | FileCheck --check-prefix=FORCED %s
|
|
|
|
; Test case from PR41294.
|
|
|
|
; Check scalar cost for extractvalue. The constant and loop invariant operands are free,
|
|
; leaving cost 3 for scalarizing the result + 2 for executing the op with VF 2.
|
|
|
|
; CM: LV: Scalar loop costs: 5.
|
|
; CM: LV: Found an estimated cost of 0 for VF 2 For instruction: %a = extractvalue { i64, i64 } %sv, 0
|
|
; CM-NEXT: LV: Found an estimated cost of 0 for VF 2 For instruction: %b = extractvalue { i64, i64 } %sv, 1
|
|
|
|
; Check that the extractvalue operands are actually free in vector code.
|
|
|
|
; FORCED-LABEL: vector.body: ; preds = %vector.body, %vector.ph
|
|
; FORCED-NEXT: %index = phi i32 [ 0, %vector.ph ], [ %index.next, %vector.body ]
|
|
; FORCED-NEXT: %0 = add i32 %index, 0
|
|
; FORCED-NEXT: %1 = extractvalue { i64, i64 } %sv, 0
|
|
; FORCED-NEXT: %2 = extractvalue { i64, i64 } %sv, 0
|
|
; FORCED-NEXT: %3 = insertelement <2 x i64> poison, i64 %1, i32 0
|
|
; FORCED-NEXT: %4 = insertelement <2 x i64> %3, i64 %2, i32 1
|
|
; FORCED-NEXT: %5 = extractvalue { i64, i64 } %sv, 1
|
|
; FORCED-NEXT: %6 = extractvalue { i64, i64 } %sv, 1
|
|
; FORCED-NEXT: %7 = insertelement <2 x i64> poison, i64 %5, i32 0
|
|
; FORCED-NEXT: %8 = insertelement <2 x i64> %7, i64 %6, i32 1
|
|
; FORCED-NEXT: %9 = getelementptr i64, i64* %dst, i32 %0
|
|
; FORCED-NEXT: %10 = add <2 x i64> %4, %8
|
|
; FORCED-NEXT: %11 = getelementptr i64, i64* %9, i32 0
|
|
; FORCED-NEXT: %12 = bitcast i64* %11 to <2 x i64>*
|
|
; FORCED-NEXT: store <2 x i64> %10, <2 x i64>* %12, align 4
|
|
; FORCED-NEXT: %index.next = add nuw i32 %index, 2
|
|
; FORCED-NEXT: %13 = icmp eq i32 %index.next, 0
|
|
; FORCED-NEXT: br i1 %13, label %middle.block, label %vector.body, !llvm.loop !0
|
|
|
|
define void @test1(i64* %dst, {i64, i64} %sv) {
|
|
entry:
|
|
br label %loop.body
|
|
|
|
loop.body:
|
|
%iv = phi i32 [ 0, %entry ], [ %iv.next, %loop.body ]
|
|
%a = extractvalue { i64, i64 } %sv, 0
|
|
%b = extractvalue { i64, i64 } %sv, 1
|
|
%addr = getelementptr i64, i64* %dst, i32 %iv
|
|
%add = add i64 %a, %b
|
|
store i64 %add, i64* %addr
|
|
%iv.next = add nsw i32 %iv, 1
|
|
%cond = icmp ne i32 %iv.next, 0
|
|
br i1 %cond, label %loop.body, label %exit
|
|
|
|
exit:
|
|
ret void
|
|
}
|
|
|
|
|
|
; Similar to the test case above, but checks getVectorCallCost as well.
|
|
declare float @pow(float, float) readnone nounwind
|
|
|
|
; CM: LV: Scalar loop costs: 14.
|
|
; CM: LV: Found an estimated cost of 0 for VF 2 For instruction: %a = extractvalue { float, float } %sv, 0
|
|
; CM-NEXT: LV: Found an estimated cost of 0 for VF 2 For instruction: %b = extractvalue { float, float } %sv, 1
|
|
|
|
; FORCED-LABEL: define void @test_getVectorCallCost
|
|
|
|
; FORCED-LABEL: vector.body: ; preds = %vector.body, %vector.ph
|
|
; FORCED-NEXT: %index = phi i32 [ 0, %vector.ph ], [ %index.next, %vector.body ]
|
|
; FORCED-NEXT: %0 = add i32 %index, 0
|
|
; FORCED-NEXT: %1 = extractvalue { float, float } %sv, 0
|
|
; FORCED-NEXT: %2 = extractvalue { float, float } %sv, 0
|
|
; FORCED-NEXT: %3 = insertelement <2 x float> poison, float %1, i32 0
|
|
; FORCED-NEXT: %4 = insertelement <2 x float> %3, float %2, i32 1
|
|
; FORCED-NEXT: %5 = extractvalue { float, float } %sv, 1
|
|
; FORCED-NEXT: %6 = extractvalue { float, float } %sv, 1
|
|
; FORCED-NEXT: %7 = insertelement <2 x float> poison, float %5, i32 0
|
|
; FORCED-NEXT: %8 = insertelement <2 x float> %7, float %6, i32 1
|
|
; FORCED-NEXT: %9 = getelementptr float, float* %dst, i32 %0
|
|
; FORCED-NEXT: %10 = call <2 x float> @llvm.pow.v2f32(<2 x float> %4, <2 x float> %8)
|
|
; FORCED-NEXT: %11 = getelementptr float, float* %9, i32 0
|
|
; FORCED-NEXT: %12 = bitcast float* %11 to <2 x float>*
|
|
; FORCED-NEXT: store <2 x float> %10, <2 x float>* %12, align 4
|
|
; FORCED-NEXT: %index.next = add nuw i32 %index, 2
|
|
; FORCED-NEXT: %13 = icmp eq i32 %index.next, 0
|
|
; FORCED-NEXT: br i1 %13, label %middle.block, label %vector.body, !llvm.loop !4
|
|
|
|
define void @test_getVectorCallCost(float* %dst, {float, float} %sv) {
|
|
entry:
|
|
br label %loop.body
|
|
|
|
loop.body:
|
|
%iv = phi i32 [ 0, %entry ], [ %iv.next, %loop.body ]
|
|
%a = extractvalue { float, float } %sv, 0
|
|
%b = extractvalue { float, float } %sv, 1
|
|
%addr = getelementptr float, float* %dst, i32 %iv
|
|
%p = call float @pow(float %a, float %b)
|
|
store float %p, float* %addr
|
|
%iv.next = add nsw i32 %iv, 1
|
|
%cond = icmp ne i32 %iv.next, 0
|
|
br i1 %cond, label %loop.body, label %exit
|
|
|
|
exit:
|
|
ret void
|
|
}
|