[llvm] [AArch64] Update cost model for extracting halves from 128+ bit vectors (PR #155601)

[Sander de Smalen via llvm-commits]

=?utf-8?q?Gaëtan?= Bossu <gaetan.bossu at arm.com>,
=?utf-8?q?Gaëtan?= Bossu <gaetan.bossu at arm.com>,
=?utf-8?q?Gaëtan?= Bossu <gaetan.bossu at arm.com>,
=?utf-8?q?Gaëtan?= Bossu <gaetan.bossu at arm.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/155601 at github.com>


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@@ -0,0 +1,339 @@
+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
+; RUN: opt < %s -mtriple=aarch64 -mattr=+sve -passes="print<cost-model>" 2>&1 -disable-output \
+; RUN:    -aarch64-sve-vector-bits-min=128 \
+; RUN:    | FileCheck %s --check-prefixes=VSCALE-ANY,VSCALE-1
+; RUN: opt < %s -mtriple=aarch64 -mattr=+sve -passes="print<cost-model>" 2>&1 -disable-output \
+; RUN:    -aarch64-sve-vector-bits-min=128 -aarch64-sve-vector-bits-max=128 \
+; RUN:    | FileCheck %s --check-prefixes=VSCALE-ANY,VSCALE-1
+; RUN: opt < %s -mtriple=aarch64 -mattr=+sve -passes="print<cost-model>" 2>&1 -disable-output \
+; RUN:    -aarch64-sve-vector-bits-min=256 \
+; RUN:    | FileCheck %s --check-prefixes=VSCALE-ANY,VSCALE-2
+; RUN: opt < %s -mtriple=aarch64 -mattr=+sve -passes="print<cost-model>" 2>&1 -disable-output \
+; RUN:    -aarch64-sve-vector-bits-min=256 -aarch64-sve-vector-bits-max=256 \
+; RUN:    | FileCheck %s --check-prefixes=VSCALE-ANY,VSCALE-2
+; RUN: opt < %s -mtriple=aarch64 -mattr=+sve -passes="print<cost-model>" 2>&1 -disable-output \
+; RUN:    -aarch64-sve-vector-bits-min=512 \
+; RUN:    | FileCheck %s --check-prefixes=VSCALE-ANY,VSCALE-4
+; RUN: opt < %s -mtriple=aarch64 -mattr=+sve -passes="print<cost-model>" 2>&1 -disable-output \
+; RUN:    -aarch64-sve-vector-bits-min=512 -aarch64-sve-vector-bits-max=512 \
+; RUN:    | FileCheck %s --check-prefixes=VSCALE-ANY,VSCALE-4
+
+; This tests the cost of fixed-length subvector extracts for SVE,
+; either for a minimum vscale or a fixed vscale (aka VLS).
+; For the NEON equivalent test, see shuffle-extract.ll
+
+define void @extract_half_lo() {
+; VSCALE-ANY-LABEL: 'extract_half_lo'
+; VSCALE-ANY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %v16i8_lo = shufflevector <16 x i8> poison, <16 x i8> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; VSCALE-ANY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %v32i8_lo = shufflevector <32 x i8> poison, <32 x i8> poison, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+; VSCALE-ANY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %v64i8_lo = shufflevector <64 x i8> poison, <64 x i8> poison, <32 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15, i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30, i32 31>
+; VSCALE-ANY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %v8i16_lo = shufflevector <8 x i16> poison, <8 x i16> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+; VSCALE-ANY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %v16i16_lo = shufflevector <16 x i16> poison, <16 x i16> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; VSCALE-ANY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %v32i16_lo = shufflevector <32 x i16> poison, <32 x i16> poison, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+; VSCALE-ANY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %v4i32_lo = shufflevector <4 x i32> poison, <4 x i32> poison, <2 x i32> <i32 0, i32 1>
+; VSCALE-ANY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %v8i32_lo = shufflevector <8 x i32> poison, <8 x i32> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+; VSCALE-ANY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %v16i32_lo = shufflevector <16 x i32> poison, <16 x i32> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; VSCALE-ANY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %v2i64_lo = shufflevector <2 x i64> poison, <2 x i64> poison, <1 x i32> zeroinitializer
+; VSCALE-ANY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %v4i64_lo = shufflevector <4 x i64> poison, <4 x i64> poison, <2 x i32> <i32 0, i32 1>
+; VSCALE-ANY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %v8i64_lo = shufflevector <8 x i64> poison, <8 x i64> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+; VSCALE-ANY-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void
+;
+  %v16i8_lo = shufflevector <16 x i8> poison, <16 x i8> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+  %v32i8_lo = shufflevector <32 x i8> poison, <32 x i8> poison, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+  %v64i8_lo = shufflevector <64 x i8> poison, <64 x i8> poison, <32 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15, i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30, i32 31>
+
+  %v8i16_lo = shufflevector <8 x i16> poison, <8 x i16> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+  %v16i16_lo = shufflevector <16 x i16> poison, <16 x i16> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+  %v32i16_lo = shufflevector <32 x i16> poison, <32 x i16> poison, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+
+  %v4i32_lo = shufflevector <4 x i32> poison, <4 x i32> poison, <2 x i32> <i32 0, i32 1>
+  %v8i32_lo = shufflevector <8 x i32> poison, <8 x i32> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+  %v16i32_lo = shufflevector <16 x i32> poison, <16 x i32> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+
+  %v2i64_lo = shufflevector <2 x i64> poison, <2 x i64> poison, <1 x i32> <i32 0>
+  %v4i64_lo = shufflevector <4 x i64> poison, <4 x i64> poison, <2 x i32> <i32 0, i32 1>
+  %v8i64_lo = shufflevector <8 x i64> poison, <8 x i64> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+
+  ret void
+}
+
+define void @extract_half_hi() {
+; VSCALE-1-LABEL: 'extract_half_hi'
+; VSCALE-1-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v16i8_hi = shufflevector <16 x i8> poison, <16 x i8> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+; VSCALE-1-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: %v32i8_hi = shufflevector <32 x i8> poison, <32 x i8> poison, <16 x i32> <i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30, i32 31>
+; VSCALE-1-NEXT:  Cost Model: Found an estimated cost of 32 for instruction: %v64i8_hi = shufflevector <64 x i8> poison, <64 x i8> poison, <32 x i32> <i32 32, i32 33, i32 34, i32 35, i32 36, i32 37, i32 38, i32 39, i32 40, i32 41, i32 42, i32 43, i32 44, i32 45, i32 46, i32 47, i32 48, i32 49, i32 50, i32 51, i32 52, i32 53, i32 54, i32 55, i32 56, i32 57, i32 58, i32 59, i32 60, i32 61, i32 62, i32 63>
+; VSCALE-1-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v8i16_hi = shufflevector <8 x i16> poison, <8 x i16> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+; VSCALE-1-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: %v16i16_hi = shufflevector <16 x i16> poison, <16 x i16> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+; VSCALE-1-NEXT:  Cost Model: Found an estimated cost of 32 for instruction: %v32i16_hi = shufflevector <32 x i16> poison, <32 x i16> poison, <16 x i32> <i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30, i32 31>
+; VSCALE-1-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v4i32_hi = shufflevector <4 x i32> poison, <4 x i32> poison, <2 x i32> <i32 2, i32 3>
+; VSCALE-1-NEXT:  Cost Model: Found an estimated cost of 6 for instruction: %v8i32_hi = shufflevector <8 x i32> poison, <8 x i32> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+; VSCALE-1-NEXT:  Cost Model: Found an estimated cost of 12 for instruction: %v16i32_hi = shufflevector <16 x i32> poison, <16 x i32> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+; VSCALE-1-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v2i64_hi = shufflevector <2 x i64> poison, <2 x i64> poison, <1 x i32> <i32 1>
+; VSCALE-1-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %v4i64_hi = shufflevector <4 x i64> poison, <4 x i64> poison, <2 x i32> <i32 2, i32 3>
+; VSCALE-1-NEXT:  Cost Model: Found an estimated cost of 4 for instruction: %v8i64_hi = shufflevector <8 x i64> poison, <8 x i64> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+; VSCALE-1-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void
+;
+; VSCALE-2-LABEL: 'extract_half_hi'
+; VSCALE-2-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v16i8_hi = shufflevector <16 x i8> poison, <16 x i8> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+; VSCALE-2-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v32i8_hi = shufflevector <32 x i8> poison, <32 x i8> poison, <16 x i32> <i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30, i32 31>
+; VSCALE-2-NEXT:  Cost Model: Found an estimated cost of 128 for instruction: %v64i8_hi = shufflevector <64 x i8> poison, <64 x i8> poison, <32 x i32> <i32 32, i32 33, i32 34, i32 35, i32 36, i32 37, i32 38, i32 39, i32 40, i32 41, i32 42, i32 43, i32 44, i32 45, i32 46, i32 47, i32 48, i32 49, i32 50, i32 51, i32 52, i32 53, i32 54, i32 55, i32 56, i32 57, i32 58, i32 59, i32 60, i32 61, i32 62, i32 63>
+; VSCALE-2-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v8i16_hi = shufflevector <8 x i16> poison, <8 x i16> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+; VSCALE-2-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v16i16_hi = shufflevector <16 x i16> poison, <16 x i16> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+; VSCALE-2-NEXT:  Cost Model: Found an estimated cost of 64 for instruction: %v32i16_hi = shufflevector <32 x i16> poison, <32 x i16> poison, <16 x i32> <i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30, i32 31>
+; VSCALE-2-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v4i32_hi = shufflevector <4 x i32> poison, <4 x i32> poison, <2 x i32> <i32 2, i32 3>
+; VSCALE-2-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v8i32_hi = shufflevector <8 x i32> poison, <8 x i32> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+; VSCALE-2-NEXT:  Cost Model: Found an estimated cost of 32 for instruction: %v16i32_hi = shufflevector <16 x i32> poison, <16 x i32> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+; VSCALE-2-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v2i64_hi = shufflevector <2 x i64> poison, <2 x i64> poison, <1 x i32> <i32 1>
+; VSCALE-2-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v4i64_hi = shufflevector <4 x i64> poison, <4 x i64> poison, <2 x i32> <i32 2, i32 3>
+; VSCALE-2-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: %v8i64_hi = shufflevector <8 x i64> poison, <8 x i64> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+; VSCALE-2-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void
+;
+; VSCALE-4-LABEL: 'extract_half_hi'
+; VSCALE-4-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v16i8_hi = shufflevector <16 x i8> poison, <16 x i8> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+; VSCALE-4-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v32i8_hi = shufflevector <32 x i8> poison, <32 x i8> poison, <16 x i32> <i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30, i32 31>
+; VSCALE-4-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %v64i8_hi = shufflevector <64 x i8> poison, <64 x i8> poison, <32 x i32> <i32 32, i32 33, i32 34, i32 35, i32 36, i32 37, i32 38, i32 39, i32 40, i32 41, i32 42, i32 43, i32 44, i32 45, i32 46, i32 47, i32 48, i32 49, i32 50, i32 51, i32 52, i32 53, i32 54, i32 55, i32 56, i32 57, i32 58, i32 59, i32 60, i32 61, i32 62, i32 63>
----------------
sdesmalen-arm wrote:

Just an observation that this could also be a cost of `0`, because if the extracted vector is a multiple of the legalised input type, and the index is a multiple of the number of elements of the legalised input type, then it would just be selecting the high registers (rather than requiring an `ext`).

https://github.com/llvm/llvm-project/pull/155601