llvm-project/llvm/test/CodeGen/AArch64/addtruncshift.ll
David Green b20d35c4a2
[AArch64] Combine vector add(trunc(shift)) (#169523)
This adds a combine for
add(trunc(ashr(A, C)), trunc(lshr(A, BW-1))), with C >= BW
->
X = trunc(ashr(A, C)); add(x, lshr(X, BW-1)

The original converts into ashr+lshr+xtn+xtn+add. The second becomes
ashr+xtn+usra. The first form has less total latency due to more
parallelism,
but more micro-ops and seems to be slower in practice.
2025-11-26 14:17:19 +00:00

115 lines
3.8 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -mtriple=aarch64-none-elf < %s | FileCheck %s --check-prefixes=CHECK,CHECK-SD
; RUN: llc -mtriple=aarch64-none-elf -global-isel < %s | FileCheck %s --check-prefixes=CHECK,CHECK-GI
define <2 x i32> @test_v2i64(<2 x i64> %n) {
; CHECK-SD-LABEL: test_v2i64:
; CHECK-SD: // %bb.0: // %entry
; CHECK-SD-NEXT: sshr v0.2d, v0.2d, #35
; CHECK-SD-NEXT: xtn v0.2s, v0.2d
; CHECK-SD-NEXT: usra v0.2s, v0.2s, #31
; CHECK-SD-NEXT: ret
;
; CHECK-GI-LABEL: test_v2i64:
; CHECK-GI: // %bb.0: // %entry
; CHECK-GI-NEXT: ushr v1.2d, v0.2d, #63
; CHECK-GI-NEXT: sshr v0.2d, v0.2d, #35
; CHECK-GI-NEXT: xtn v1.2s, v1.2d
; CHECK-GI-NEXT: xtn v0.2s, v0.2d
; CHECK-GI-NEXT: add v0.2s, v1.2s, v0.2s
; CHECK-GI-NEXT: ret
entry:
%shr = lshr <2 x i64> %n, splat (i64 63)
%vmovn.i4 = trunc nuw nsw <2 x i64> %shr to <2 x i32>
%shr1 = ashr <2 x i64> %n, splat (i64 35)
%vmovn.i = trunc nsw <2 x i64> %shr1 to <2 x i32>
%add = add nsw <2 x i32> %vmovn.i4, %vmovn.i
ret <2 x i32> %add
}
define <4 x i16> @test_v4i32(<4 x i32> %n) {
; CHECK-SD-LABEL: test_v4i32:
; CHECK-SD: // %bb.0: // %entry
; CHECK-SD-NEXT: sshr v0.4s, v0.4s, #17
; CHECK-SD-NEXT: xtn v0.4h, v0.4s
; CHECK-SD-NEXT: usra v0.4h, v0.4h, #15
; CHECK-SD-NEXT: ret
;
; CHECK-GI-LABEL: test_v4i32:
; CHECK-GI: // %bb.0: // %entry
; CHECK-GI-NEXT: ushr v1.4s, v0.4s, #31
; CHECK-GI-NEXT: sshr v0.4s, v0.4s, #17
; CHECK-GI-NEXT: xtn v1.4h, v1.4s
; CHECK-GI-NEXT: xtn v0.4h, v0.4s
; CHECK-GI-NEXT: add v0.4h, v1.4h, v0.4h
; CHECK-GI-NEXT: ret
entry:
%shr = lshr <4 x i32> %n, splat (i32 31)
%vmovn.i4 = trunc nuw nsw <4 x i32> %shr to <4 x i16>
%shr1 = ashr <4 x i32> %n, splat (i32 17)
%vmovn.i = trunc nsw <4 x i32> %shr1 to <4 x i16>
%add = add nsw <4 x i16> %vmovn.i4, %vmovn.i
ret <4 x i16> %add
}
define <8 x i8> @test_v8i16(<8 x i16> %n) {
; CHECK-SD-LABEL: test_v8i16:
; CHECK-SD: // %bb.0: // %entry
; CHECK-SD-NEXT: sshr v0.8h, v0.8h, #9
; CHECK-SD-NEXT: xtn v0.8b, v0.8h
; CHECK-SD-NEXT: usra v0.8b, v0.8b, #7
; CHECK-SD-NEXT: ret
;
; CHECK-GI-LABEL: test_v8i16:
; CHECK-GI: // %bb.0: // %entry
; CHECK-GI-NEXT: ushr v1.8h, v0.8h, #15
; CHECK-GI-NEXT: sshr v0.8h, v0.8h, #9
; CHECK-GI-NEXT: xtn v1.8b, v1.8h
; CHECK-GI-NEXT: xtn v0.8b, v0.8h
; CHECK-GI-NEXT: add v0.8b, v1.8b, v0.8b
; CHECK-GI-NEXT: ret
entry:
%shr = lshr <8 x i16> %n, splat (i16 15)
%vmovn.i4 = trunc nuw nsw <8 x i16> %shr to <8 x i8>
%shr1 = ashr <8 x i16> %n, splat (i16 9)
%vmovn.i = trunc nsw <8 x i16> %shr1 to <8 x i8>
%add = add nsw <8 x i8> %vmovn.i4, %vmovn.i
ret <8 x i8> %add
}
define <2 x i32> @test_v2i64_smallsrl(<2 x i64> %n) {
; CHECK-LABEL: test_v2i64_smallsrl:
; CHECK: // %bb.0: // %entry
; CHECK-NEXT: ushr v1.2d, v0.2d, #62
; CHECK-NEXT: sshr v0.2d, v0.2d, #35
; CHECK-NEXT: xtn v1.2s, v1.2d
; CHECK-NEXT: xtn v0.2s, v0.2d
; CHECK-NEXT: add v0.2s, v1.2s, v0.2s
; CHECK-NEXT: ret
entry:
%shr = lshr <2 x i64> %n, splat (i64 62)
%vmovn.i4 = trunc nuw nsw <2 x i64> %shr to <2 x i32>
%shr1 = ashr <2 x i64> %n, splat (i64 35)
%vmovn.i = trunc nsw <2 x i64> %shr1 to <2 x i32>
%add = add nsw <2 x i32> %vmovn.i4, %vmovn.i
ret <2 x i32> %add
}
define <2 x i32> @test_v2i64_smallsra(<2 x i64> %n) {
; CHECK-LABEL: test_v2i64_smallsra:
; CHECK: // %bb.0: // %entry
; CHECK-NEXT: ushr v1.2d, v0.2d, #63
; CHECK-NEXT: shrn v0.2s, v0.2d, #27
; CHECK-NEXT: xtn v1.2s, v1.2d
; CHECK-NEXT: add v0.2s, v1.2s, v0.2s
; CHECK-NEXT: ret
entry:
%shr = lshr <2 x i64> %n, splat (i64 63)
%vmovn.i4 = trunc nuw nsw <2 x i64> %shr to <2 x i32>
%shr1 = ashr <2 x i64> %n, splat (i64 27)
%vmovn.i = trunc nsw <2 x i64> %shr1 to <2 x i32>
%add = add nsw <2 x i32> %vmovn.i4, %vmovn.i
ret <2 x i32> %add
}