[AArch64] Pre-commit test case to show sub-optimal codegen for Github issue #57502

Pre-commit test cases to show cases when UZP1 (TRUNC, TRUNC) could be
combined into TRUNC (UZP1) (with some proper bit conversions in the middle) to generate more efficient code.

Differential Revision: https://reviews.llvm.org/D133280

diff --git a/llvm/test/CodeGen/AArch64/aarch64-uzp1-combine.ll b/llvm/test/CodeGen/AArch64/aarch64-uzp1-combine.ll
new file mode 100644 (file)
index 0000000..7f81ff6
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/aarch64-uzp1-combine.ll
@@ -0,0 +1,313 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple aarch64-none-linux-gnu | FileCheck --check-prefix=CHECK-LE %s
+; RUN: llc < %s -mtriple aarch64_be-none-linux-gnu | FileCheck --check-prefix=CHECK-BE %s
+
+; Test cases to show when UZP1 (TRUNC, TRUNC) could be combined to TRUNC (UZP1) but not yet implemented.
+
+define <4 x i16> @test_combine_v4i16_v2i64(<2 x i64> %a, <2 x i64> %b) {
+; CHECK-LE-LABEL: test_combine_v4i16_v2i64:
+; CHECK-LE:       // %bb.0:
+; CHECK-LE-NEXT:    xtn v0.2s, v0.2d
+; CHECK-LE-NEXT:    xtn v1.2s, v1.2d
+; CHECK-LE-NEXT:    uzp1 v0.4h, v0.4h, v1.4h
+; CHECK-LE-NEXT:    ret
+;
+; CHECK-BE-LABEL: test_combine_v4i16_v2i64:
+; CHECK-BE:       // %bb.0:
+; CHECK-BE-NEXT:    ext v1.16b, v1.16b, v1.16b, #8
+; CHECK-BE-NEXT:    ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-BE-NEXT:    xtn v1.2s, v1.2d
+; CHECK-BE-NEXT:    xtn v0.2s, v0.2d
+; CHECK-BE-NEXT:    rev32 v1.4h, v1.4h
+; CHECK-BE-NEXT:    rev32 v0.4h, v0.4h
+; CHECK-BE-NEXT:    uzp1 v0.4h, v0.4h, v1.4h
+; CHECK-BE-NEXT:    rev64 v0.4h, v0.4h
+; CHECK-BE-NEXT:    ret
+  %a1 = trunc <2 x i64> %a to <2 x i32>
+  %b1 = trunc <2 x i64> %b to <2 x i32>
+
+  %a2 = bitcast <2 x i32> %a1 to <4 x i16>
+  %b2 = bitcast <2 x i32> %b1 to <4 x i16>
+
+  %ab = shufflevector <4 x i16> %a2, <4 x i16> %b2, <4 x i32> <i32 0, i32 2, i32 4, i32 6>
+  ret <4 x i16> %ab
+}
+
+define <4 x i16> @test_combine_v4i16_v4i32(<4 x i32> %a, <4 x i32> %b) {
+; CHECK-LE-LABEL: test_combine_v4i16_v4i32:
+; CHECK-LE:       // %bb.0:
+; CHECK-LE-NEXT:    xtn v0.4h, v0.4s
+; CHECK-LE-NEXT:    xtn v1.4h, v1.4s
+; CHECK-LE-NEXT:    uzp1 v0.4h, v0.4h, v1.4h
+; CHECK-LE-NEXT:    ret
+;
+; CHECK-BE-LABEL: test_combine_v4i16_v4i32:
+; CHECK-BE:       // %bb.0:
+; CHECK-BE-NEXT:    rev64 v1.4s, v1.4s
+; CHECK-BE-NEXT:    rev64 v0.4s, v0.4s
+; CHECK-BE-NEXT:    ext v1.16b, v1.16b, v1.16b, #8
+; CHECK-BE-NEXT:    ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-BE-NEXT:    xtn v1.4h, v1.4s
+; CHECK-BE-NEXT:    xtn v0.4h, v0.4s
+; CHECK-BE-NEXT:    uzp1 v0.4h, v0.4h, v1.4h
+; CHECK-BE-NEXT:    rev64 v0.4h, v0.4h
+; CHECK-BE-NEXT:    ret
+  %a1 = trunc <4 x i32> %a to <4 x i16>
+  %b1 = trunc <4 x i32> %b to <4 x i16>
+
+  %ab = shufflevector <4 x i16> %a1, <4 x i16> %b1, <4 x i32> <i32 0, i32 2, i32 4, i32 6>
+  ret <4 x i16> %ab
+}
+
+define <4 x i16> @test_combine_v4i16_v8i16(<8 x i16> %a, <8 x i16> %b) {
+; CHECK-LE-LABEL: test_combine_v4i16_v8i16:
+; CHECK-LE:       // %bb.0:
+; CHECK-LE-NEXT:    xtn v0.8b, v0.8h
+; CHECK-LE-NEXT:    xtn v1.8b, v1.8h
+; CHECK-LE-NEXT:    uzp1 v0.4h, v0.4h, v1.4h
+; CHECK-LE-NEXT:    ret
+;
+; CHECK-BE-LABEL: test_combine_v4i16_v8i16:
+; CHECK-BE:       // %bb.0:
+; CHECK-BE-NEXT:    rev64 v1.8h, v1.8h
+; CHECK-BE-NEXT:    rev64 v0.8h, v0.8h
+; CHECK-BE-NEXT:    ext v1.16b, v1.16b, v1.16b, #8
+; CHECK-BE-NEXT:    ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-BE-NEXT:    xtn v1.8b, v1.8h
+; CHECK-BE-NEXT:    xtn v0.8b, v0.8h
+; CHECK-BE-NEXT:    rev16 v1.8b, v1.8b
+; CHECK-BE-NEXT:    rev16 v0.8b, v0.8b
+; CHECK-BE-NEXT:    uzp1 v0.4h, v0.4h, v1.4h
+; CHECK-BE-NEXT:    rev64 v0.4h, v0.4h
+; CHECK-BE-NEXT:    ret
+  %a1 = trunc <8 x i16> %a to <8 x i8>
+  %b1 = trunc <8 x i16> %b to <8 x i8>
+
+  %a2 = bitcast <8 x i8> %a1 to <4 x i16>
+  %b2 = bitcast <8 x i8> %b1 to <4 x i16>
+
+  %ab = shufflevector <4 x i16> %a2, <4 x i16> %b2, <4 x i32> <i32 0, i32 2, i32 4, i32 6>
+  ret <4 x i16> %ab
+}
+
+
+define <8 x i8> @test_combine_v8i8_v2i64(<2 x i64> %a, <2 x i64> %b) {
+; CHECK-LE-LABEL: test_combine_v8i8_v2i64:
+; CHECK-LE:       // %bb.0:
+; CHECK-LE-NEXT:    xtn v0.2s, v0.2d
+; CHECK-LE-NEXT:    xtn v1.2s, v1.2d
+; CHECK-LE-NEXT:    uzp1 v0.8b, v0.8b, v1.8b
+; CHECK-LE-NEXT:    ret
+;
+; CHECK-BE-LABEL: test_combine_v8i8_v2i64:
+; CHECK-BE:       // %bb.0:
+; CHECK-BE-NEXT:    ext v1.16b, v1.16b, v1.16b, #8
+; CHECK-BE-NEXT:    ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-BE-NEXT:    xtn v1.2s, v1.2d
+; CHECK-BE-NEXT:    xtn v0.2s, v0.2d
+; CHECK-BE-NEXT:    rev32 v1.8b, v1.8b
+; CHECK-BE-NEXT:    rev32 v0.8b, v0.8b
+; CHECK-BE-NEXT:    uzp1 v0.8b, v0.8b, v1.8b
+; CHECK-BE-NEXT:    rev64 v0.8b, v0.8b
+; CHECK-BE-NEXT:    ret
+  %a1 = trunc <2 x i64> %a to <2 x i32>
+  %b1 = trunc <2 x i64> %b to <2 x i32>
+
+  %a2 = bitcast <2 x i32> %a1 to <8 x i8>
+  %b2 = bitcast <2 x i32> %b1 to <8 x i8>
+
+  %ab = shufflevector <8 x i8> %a2, <8 x i8> %b2, <8 x i32> <i32 0, i32 2, i32 4, i32 6, i32 8, i32 10, i32 12, i32 14>
+  ret <8 x i8> %ab
+}
+
+define <8 x i8> @test_combine_v8i8_v4i32(<4 x i32> %a, <4 x i32> %b) {
+; CHECK-LE-LABEL: test_combine_v8i8_v4i32:
+; CHECK-LE:       // %bb.0:
+; CHECK-LE-NEXT:    xtn v0.4h, v0.4s
+; CHECK-LE-NEXT:    xtn v1.4h, v1.4s
+; CHECK-LE-NEXT:    uzp1 v0.8b, v0.8b, v1.8b
+; CHECK-LE-NEXT:    ret
+;
+; CHECK-BE-LABEL: test_combine_v8i8_v4i32:
+; CHECK-BE:       // %bb.0:
+; CHECK-BE-NEXT:    rev64 v1.4s, v1.4s
+; CHECK-BE-NEXT:    rev64 v0.4s, v0.4s
+; CHECK-BE-NEXT:    ext v1.16b, v1.16b, v1.16b, #8
+; CHECK-BE-NEXT:    ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-BE-NEXT:    xtn v1.4h, v1.4s
+; CHECK-BE-NEXT:    xtn v0.4h, v0.4s
+; CHECK-BE-NEXT:    rev16 v1.8b, v1.8b
+; CHECK-BE-NEXT:    rev16 v0.8b, v0.8b
+; CHECK-BE-NEXT:    uzp1 v0.8b, v0.8b, v1.8b
+; CHECK-BE-NEXT:    rev64 v0.8b, v0.8b
+; CHECK-BE-NEXT:    ret
+  %a1 = trunc <4 x i32> %a to <4 x i16>
+  %b1 = trunc <4 x i32> %b to <4 x i16>
+
+  %a2 = bitcast <4 x i16> %a1 to <8 x i8>
+  %b2 = bitcast <4 x i16> %b1 to <8 x i8>
+
+  %ab = shufflevector <8 x i8> %a2, <8 x i8> %b2, <8 x i32> <i32 0, i32 2, i32 4, i32 6, i32 8, i32 10, i32 12, i32 14>
+  ret <8 x i8> %ab
+}
+
+define <8 x i8> @test_combine_v8i8_v8i16(<8 x i16> %a, <8 x i16> %b) {
+; CHECK-LE-LABEL: test_combine_v8i8_v8i16:
+; CHECK-LE:       // %bb.0:
+; CHECK-LE-NEXT:    xtn v0.8b, v0.8h
+; CHECK-LE-NEXT:    xtn v1.8b, v1.8h
+; CHECK-LE-NEXT:    uzp1 v0.8b, v0.8b, v1.8b
+; CHECK-LE-NEXT:    ret
+;
+; CHECK-BE-LABEL: test_combine_v8i8_v8i16:
+; CHECK-BE:       // %bb.0:
+; CHECK-BE-NEXT:    rev64 v1.8h, v1.8h
+; CHECK-BE-NEXT:    rev64 v0.8h, v0.8h
+; CHECK-BE-NEXT:    ext v1.16b, v1.16b, v1.16b, #8
+; CHECK-BE-NEXT:    ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-BE-NEXT:    xtn v1.8b, v1.8h
+; CHECK-BE-NEXT:    xtn v0.8b, v0.8h
+; CHECK-BE-NEXT:    uzp1 v0.8b, v0.8b, v1.8b
+; CHECK-BE-NEXT:    rev64 v0.8b, v0.8b
+; CHECK-BE-NEXT:    ret
+  %a1 = trunc <8 x i16> %a to <8 x i8>
+  %b1 = trunc <8 x i16> %b to <8 x i8>
+
+  %ab = shufflevector <8 x i8> %a1, <8 x i8> %b1, <8 x i32> <i32 0, i32 2, i32 4, i32 6, i32 8, i32 10, i32 12, i32 14>
+  ret <8 x i8> %ab
+}
+
+define <2 x i32> @test_combine_v2i32_v2i64(<2 x i64> %a, <2 x i64> %b) {
+; CHECK-LE-LABEL: test_combine_v2i32_v2i64:
+; CHECK-LE:       // %bb.0:
+; CHECK-LE-NEXT:    xtn v0.2s, v0.2d
+; CHECK-LE-NEXT:    xtn v1.2s, v1.2d
+; CHECK-LE-NEXT:    zip1 v0.2s, v0.2s, v1.2s
+; CHECK-LE-NEXT:    ret
+;
+; CHECK-BE-LABEL: test_combine_v2i32_v2i64:
+; CHECK-BE:       // %bb.0:
+; CHECK-BE-NEXT:    ext v1.16b, v1.16b, v1.16b, #8
+; CHECK-BE-NEXT:    ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-BE-NEXT:    xtn v1.2s, v1.2d
+; CHECK-BE-NEXT:    xtn v0.2s, v0.2d
+; CHECK-BE-NEXT:    zip1 v0.2s, v0.2s, v1.2s
+; CHECK-BE-NEXT:    rev64 v0.2s, v0.2s
+; CHECK-BE-NEXT:    ret
+  %a1 = trunc <2 x i64> %a to <2 x i32>
+  %b1 = trunc <2 x i64> %b to <2 x i32>
+
+  %ab = shufflevector <2 x i32> %a1, <2 x i32> %b1, <2 x i32> <i32 0, i32 2>
+  ret <2 x i32> %ab
+}
+
+define <2 x i32> @test_combine_v2i32_v4i32(<4 x i32> %a, <4 x i32> %b) {
+; CHECK-LE-LABEL: test_combine_v2i32_v4i32:
+; CHECK-LE:       // %bb.0:
+; CHECK-LE-NEXT:    xtn v0.4h, v0.4s
+; CHECK-LE-NEXT:    xtn v1.4h, v1.4s
+; CHECK-LE-NEXT:    zip1 v0.2s, v0.2s, v1.2s
+; CHECK-LE-NEXT:    ret
+;
+; CHECK-BE-LABEL: test_combine_v2i32_v4i32:
+; CHECK-BE:       // %bb.0:
+; CHECK-BE-NEXT:    rev64 v1.4s, v1.4s
+; CHECK-BE-NEXT:    rev64 v0.4s, v0.4s
+; CHECK-BE-NEXT:    ext v1.16b, v1.16b, v1.16b, #8
+; CHECK-BE-NEXT:    ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-BE-NEXT:    xtn v1.4h, v1.4s
+; CHECK-BE-NEXT:    xtn v0.4h, v0.4s
+; CHECK-BE-NEXT:    rev32 v1.4h, v1.4h
+; CHECK-BE-NEXT:    rev32 v0.4h, v0.4h
+; CHECK-BE-NEXT:    zip1 v0.2s, v0.2s, v1.2s
+; CHECK-BE-NEXT:    rev64 v0.2s, v0.2s
+; CHECK-BE-NEXT:    ret
+  %a1 = trunc <4 x i32> %a to <4 x i16>
+  %b1 = trunc <4 x i32> %b to <4 x i16>
+
+  %a2 = bitcast <4 x i16> %a1 to <2 x i32>
+  %b2 = bitcast <4 x i16> %b1 to <2 x i32>
+
+  %ab = shufflevector <2 x i32> %a2, <2 x i32> %b2, <2 x i32> <i32 0, i32 2>
+  ret <2 x i32> %ab
+}
+
+define <2 x i32> @test_combine_v2i32_v8i16(<8 x i16> %a, <8 x i16> %b) {
+; CHECK-LE-LABEL: test_combine_v2i32_v8i16:
+; CHECK-LE:       // %bb.0:
+; CHECK-LE-NEXT:    xtn v0.8b, v0.8h
+; CHECK-LE-NEXT:    xtn v1.8b, v1.8h
+; CHECK-LE-NEXT:    zip1 v0.2s, v0.2s, v1.2s
+; CHECK-LE-NEXT:    ret
+;
+; CHECK-BE-LABEL: test_combine_v2i32_v8i16:
+; CHECK-BE:       // %bb.0:
+; CHECK-BE-NEXT:    rev64 v1.8h, v1.8h
+; CHECK-BE-NEXT:    rev64 v0.8h, v0.8h
+; CHECK-BE-NEXT:    ext v1.16b, v1.16b, v1.16b, #8
+; CHECK-BE-NEXT:    ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-BE-NEXT:    xtn v1.8b, v1.8h
+; CHECK-BE-NEXT:    xtn v0.8b, v0.8h
+; CHECK-BE-NEXT:    rev32 v1.8b, v1.8b
+; CHECK-BE-NEXT:    rev32 v0.8b, v0.8b
+; CHECK-BE-NEXT:    zip1 v0.2s, v0.2s, v1.2s
+; CHECK-BE-NEXT:    rev64 v0.2s, v0.2s
+; CHECK-BE-NEXT:    ret
+  %a1 = trunc <8 x i16> %a to <8 x i8>
+  %b1 = trunc <8 x i16> %b to <8 x i8>
+
+  %a2 = bitcast <8 x i8> %a1 to <2 x i32>
+  %b2 = bitcast <8 x i8> %b1 to <2 x i32>
+
+  %ab = shufflevector <2 x i32> %a2, <2 x i32> %b2, <2 x i32> <i32 0, i32 2>
+  ret <2 x i32> %ab
+}
+
+define i8 @trunc_v4i64_v4i8(<4 x i64> %input) {
+; CHECK-LE-LABEL: trunc_v4i64_v4i8:
+; CHECK-LE:       // %bb.0:
+; CHECK-LE-NEXT:    xtn v1.2s, v1.2d
+; CHECK-LE-NEXT:    xtn v0.2s, v0.2d
+; CHECK-LE-NEXT:    uzp1 v0.4h, v0.4h, v1.4h
+; CHECK-LE-NEXT:    addv h0, v0.4h
+; CHECK-LE-NEXT:    fmov w0, s0
+; CHECK-LE-NEXT:    ret
+;
+; CHECK-BE-LABEL: trunc_v4i64_v4i8:
+; CHECK-BE:       // %bb.0:
+; CHECK-BE-NEXT:    ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-BE-NEXT:    ext v1.16b, v1.16b, v1.16b, #8
+; CHECK-BE-NEXT:    xtn v0.2s, v0.2d
+; CHECK-BE-NEXT:    xtn v1.2s, v1.2d
+; CHECK-BE-NEXT:    rev32 v0.4h, v0.4h
+; CHECK-BE-NEXT:    rev32 v1.4h, v1.4h
+; CHECK-BE-NEXT:    uzp1 v0.4h, v0.4h, v1.4h
+; CHECK-BE-NEXT:    addv h0, v0.4h
+; CHECK-BE-NEXT:    fmov w0, s0
+; CHECK-BE-NEXT:    ret
+  %var = trunc <4 x i64> %input to <4 x i8>
+  ; llvm.vector.reduce.add.v4i8 is needed to reproduce the codegen (see `trunc_v4i64_v4i8_ret` below as a comparison)
+  %res = call i8 @llvm.vector.reduce.add.v4i8(<4 x i8> %var)
+  ret i8 %res
+}
+
+define <4 x i8> @trunc_v4i64_v4i8_ret(<4 x i64> %input) {
+; CHECK-LE-LABEL: trunc_v4i64_v4i8_ret:
+; CHECK-LE:       // %bb.0:
+; CHECK-LE-NEXT:    uzp1 v0.4s, v0.4s, v1.4s
+; CHECK-LE-NEXT:    xtn v0.4h, v0.4s
+; CHECK-LE-NEXT:    ret
+;
+; CHECK-BE-LABEL: trunc_v4i64_v4i8_ret:
+; CHECK-BE:       // %bb.0:
+; CHECK-BE-NEXT:    ext v1.16b, v1.16b, v1.16b, #8
+; CHECK-BE-NEXT:    ext v0.16b, v0.16b, v0.16b, #8
+; CHECK-BE-NEXT:    uzp1 v0.4s, v0.4s, v1.4s
+; CHECK-BE-NEXT:    xtn v0.4h, v0.4s
+; CHECK-BE-NEXT:    rev64 v0.4h, v0.4h
+; CHECK-BE-NEXT:    ret
+  %var = trunc <4 x i64> %input to <4 x i8>
+  ret <4 x i8> %var
+}
+
+declare i8 @llvm.vector.reduce.add.v4i8(<4 x i8>)