[LegalizeVectorTypes] Allow single loads and stores for more short vectors

When lowering a load or store for TypeWidenVector, the type legalizer
would use a single load or store if the associated integer type was legal
or promoted. E.g. it loads a v4i8 as an i32 if i32 is legal/promotable.
(See https://reviews.llvm.org/rL236528 for reference.)

This applies that behaviour to vector types. If the vector type is
TypePromoteInteger, the element type is going to be TypePromoteInteger
as well, which will lead to have a single promoting load rather than N
individual promoting loads. For instance, if we have a v3i1, we would
now have a load of v4i1 instead of 3 loads of i1.

Patch by Guillaume Marques. Thanks!

Differential Revision: https://reviews.llvm.org/D56201

llvm-svn: 357120

1 files changed, 70 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/X86/load-local-v3i1.ll b/llvm/test/CodeGen/X86/load-local-v3i1.ll
new file mode 100644
index 00000000000..88b87c273e8
--- /dev/null
+++ b/llvm/test/CodeGen/X86/load-local-v3i1.ll
@@ -0,0 +1,70 @@
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+sse4.2 | FileCheck %s
+
+; widen a v3i1 to v4i1 to do a vector load/store. We would previously
+; reconstruct the said v3i1 from the first element of the vector by filling all
+; the lanes of the vector with that first element, which was obviously wrong.
+; This was done in the type-legalizing of the DAG, when legalizing the load.
+
+; Function Attrs: argmemonly nounwind readonly
+declare <3 x i32> @llvm.masked.load.v3i32.p1v3i32(<3 x i32> addrspace(1)*, i32, <3 x i1>, <3 x i32>)
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.masked.store.v3i32.p1v3i32(<3 x i32>, <3 x i32> addrspace(1)*, i32, <3 x i1>)
+
+define  <3 x i32> @masked_load_v3(i32 addrspace(1)*, <3 x i1>) {
+entry:
+  %2 = bitcast i32 addrspace(1)* %0 to <3 x i32> addrspace(1)*
+  %3 = call <3 x i32> @llvm.masked.load.v3i32.p1v3i32(<3 x i32> addrspace(1)* %2, i32 4, <3 x i1> %1, <3 x i32> undef)
+  ret <3 x i32> %3
+}
+
+define void @masked_store4_v3(<3 x i32>, i32 addrspace(1)*, <3 x i1>) {
+entry:
+  %3 = bitcast i32 addrspace(1)* %1 to <3 x i32> addrspace(1)*
+  call void @llvm.masked.store.v3i32.p1v3i32(<3 x i32> %0, <3 x i32> addrspace(1)* %3, i32 4, <3 x i1> %2)
+  ret void
+}
+
+define void @local_load_v3i1(i32 addrspace(1)* %out, i32 addrspace(1)* %in, <3 x i1>* %predicate_ptr) nounwind {
+; CHECK-LABEL: local_load_v3i1:
+; CHECK:       # %bb.0:
+; CHECK-NEXT: pushq   %rbp
+; CHECK-NEXT: pushq   %r15
+; CHECK-NEXT: pushq   %r14
+; CHECK-NEXT: pushq   %rbx
+; CHECK-NEXT: pushq   %rax
+; CHECK-NEXT: movq    %rdi, %r14
+; CHECK-NEXT: movzbl  (%rdx), %ebp
+; CHECK-NEXT: movl    %ebp, %eax
+; CHECK-NEXT: shrl    %eax
+; CHECK-NEXT: andl    $1, %eax
+; CHECK-NEXT: movl    %ebp, %ecx
+; CHECK-NEXT: andl    $1, %ecx
+; CHECK-NEXT: movd    %ecx, %xmm0
+; CHECK-NEXT: pinsrd  $1, %eax, %xmm0
+; CHECK-NEXT: shrl    $2, %ebp
+; CHECK-NEXT: andl    $1, %ebp
+; CHECK-NEXT: pinsrd  $2, %ebp, %xmm0
+; CHECK-NEXT: movd    %xmm0, %ebx
+; CHECK-NEXT: pextrd  $1, %xmm0, %r15d
+; CHECK-NEXT: movq    %rsi, %rdi
+; CHECK-NEXT: movl    %ebx, %esi
+; CHECK-NEXT: movl    %r15d, %edx
+; CHECK-NEXT: movl    %ebp, %ecx
+; CHECK-NEXT: callq   masked_load_v3
+; CHECK-NEXT: movq    %r14, %rdi
+; CHECK-NEXT: movl    %ebx, %esi
+; CHECK-NEXT: movl    %r15d, %edx
+; CHECK-NEXT: movl    %ebp, %ecx
+; CHECK-NEXT: callq   masked_store4_v3
+; CHECK-NEXT: addq    $8, %rsp
+; CHECK-NEXT: popq    %rbx
+; CHECK-NEXT: popq    %r14
+; CHECK-NEXT: popq    %r15
+; CHECK-NEXT: popq    %rbp
+; CHECK-NEXT: retq
+  %predicate = load <3 x i1>, <3 x i1>* %predicate_ptr
+  %load1 = call <3 x i32> @masked_load_v3(i32 addrspace(1)* %in, <3 x i1> %predicate)
+  call void @masked_store4_v3(<3 x i32> %load1, i32 addrspace(1)* %out, <3 x i1> %predicate)
+  ret void
+}