[VectorCombine] add tests for possible scalarization; NFC

diff --git a/llvm/test/Transforms/VectorCombine/X86/insert-binop.ll b/llvm/test/Transforms/VectorCombine/X86/insert-binop.ll
new file mode 100644 (file)
index 0000000..06f399e
--- /dev/null
+++ b/llvm/test/Transforms/VectorCombine/X86/insert-binop.ll
@@ -0,0 +1,97 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -vector-combine -S -mtriple=x86_64-- -mattr=SSE2 | FileCheck %s --check-prefixes=CHECK,SSE
+; RUN: opt < %s -vector-combine -S -mtriple=x86_64-- -mattr=AVX2 | FileCheck %s --check-prefixes=CHECK,AVX
+
+declare void @use(<4 x i32>)
+
+; Eliminating an insert is profitable.
+
+define <16 x i8> @ins0_ins0_add(i8 %x, i8 %y) {
+; CHECK-LABEL: @ins0_ins0_add(
+; CHECK-NEXT:    [[I0:%.*]] = insertelement <16 x i8> undef, i8 [[X:%.*]], i32 0
+; CHECK-NEXT:    [[I1:%.*]] = insertelement <16 x i8> undef, i8 [[Y:%.*]], i32 0
+; CHECK-NEXT:    [[R:%.*]] = add <16 x i8> [[I0]], [[I1]]
+; CHECK-NEXT:    ret <16 x i8> [[R]]
+;
+  %i0 = insertelement <16 x i8> undef, i8 %x, i32 0
+  %i1 = insertelement <16 x i8> undef, i8 %y, i32 0
+  %r = add <16 x i8> %i0, %i1
+  ret <16 x i8> %r
+}
+
+; Eliminating an insert is still profitable. Flags propagate. Mismatch types on index is ok.
+
+define <8 x i16> @ins0_ins0_sub_flags(i16 %x, i16 %y) {
+; CHECK-LABEL: @ins0_ins0_sub_flags(
+; CHECK-NEXT:    [[I0:%.*]] = insertelement <8 x i16> undef, i16 [[X:%.*]], i8 5
+; CHECK-NEXT:    [[I1:%.*]] = insertelement <8 x i16> undef, i16 [[Y:%.*]], i32 5
+; CHECK-NEXT:    [[R:%.*]] = sub nuw nsw <8 x i16> [[I0]], [[I1]]
+; CHECK-NEXT:    ret <8 x i16> [[R]]
+;
+  %i0 = insertelement <8 x i16> undef, i16 %x, i8 5
+  %i1 = insertelement <8 x i16> undef, i16 %y, i32 5
+  %r = sub nsw nuw <8 x i16> %i0, %i1
+  ret <8 x i16> %r
+}
+
+; The inserts are free, but it's still better to scalarize.
+
+define <2 x double> @ins0_ins0_fadd(double %x, double %y) {
+; CHECK-LABEL: @ins0_ins0_fadd(
+; CHECK-NEXT:    [[I0:%.*]] = insertelement <2 x double> undef, double [[X:%.*]], i32 0
+; CHECK-NEXT:    [[I1:%.*]] = insertelement <2 x double> undef, double [[Y:%.*]], i32 0
+; CHECK-NEXT:    [[R:%.*]] = fadd reassoc nsz <2 x double> [[I0]], [[I1]]
+; CHECK-NEXT:    ret <2 x double> [[R]]
+;
+  %i0 = insertelement <2 x double> undef, double %x, i32 0
+  %i1 = insertelement <2 x double> undef, double %y, i32 0
+  %r = fadd reassoc nsz <2 x double> %i0, %i1
+  ret <2 x double> %r
+}
+
+; Negative test - mismatched indexes. This could simplify.
+
+define <16 x i8> @ins1_ins0_add(i8 %x, i8 %y) {
+; CHECK-LABEL: @ins1_ins0_add(
+; CHECK-NEXT:    [[I0:%.*]] = insertelement <16 x i8> undef, i8 [[X:%.*]], i32 1
+; CHECK-NEXT:    [[I1:%.*]] = insertelement <16 x i8> undef, i8 [[Y:%.*]], i32 0
+; CHECK-NEXT:    [[R:%.*]] = add <16 x i8> [[I0]], [[I1]]
+; CHECK-NEXT:    ret <16 x i8> [[R]]
+;
+  %i0 = insertelement <16 x i8> undef, i8 %x, i32 1
+  %i1 = insertelement <16 x i8> undef, i8 %y, i32 0
+  %r = add <16 x i8> %i0, %i1
+  ret <16 x i8> %r
+}
+
+; Negative test - not undef base vector. This could fold.
+
+define <4 x i32> @ins0_ins0_mul(i32 %x, i32 %y) {
+; CHECK-LABEL: @ins0_ins0_mul(
+; CHECK-NEXT:    [[I0:%.*]] = insertelement <4 x i32> zeroinitializer, i32 [[X:%.*]], i32 0
+; CHECK-NEXT:    [[I1:%.*]] = insertelement <4 x i32> undef, i32 [[Y:%.*]], i32 0
+; CHECK-NEXT:    [[R:%.*]] = mul <4 x i32> [[I0]], [[I1]]
+; CHECK-NEXT:    ret <4 x i32> [[R]]
+;
+  %i0 = insertelement <4 x i32> zeroinitializer, i32 %x, i32 0
+  %i1 = insertelement <4 x i32> undef, i32 %y, i32 0
+  %r = mul <4 x i32> %i0, %i1
+  ret <4 x i32> %r
+}
+
+; Negative test - extra use. This could fold.
+
+define <4 x i32> @ins0_ins0_xor(i32 %x, i32 %y) {
+; CHECK-LABEL: @ins0_ins0_xor(
+; CHECK-NEXT:    [[I0:%.*]] = insertelement <4 x i32> undef, i32 [[X:%.*]], i32 0
+; CHECK-NEXT:    call void @use(<4 x i32> [[I0]])
+; CHECK-NEXT:    [[I1:%.*]] = insertelement <4 x i32> undef, i32 [[Y:%.*]], i32 0
+; CHECK-NEXT:    [[R:%.*]] = xor <4 x i32> [[I0]], [[I1]]
+; CHECK-NEXT:    ret <4 x i32> [[R]]
+;
+  %i0 = insertelement <4 x i32> undef, i32 %x, i32 0
+  call void @use(<4 x i32> %i0)
+  %i1 = insertelement <4 x i32> undef, i32 %y, i32 0
+  %r = xor <4 x i32> %i0, %i1
+  ret <4 x i32> %r
+}