[ARM] Add ARMISD::VLD1DUP to match vld1_dup more consistently.

Currently, there are substantial problems forming vld1_dup even if the
VDUP survives legalization. The lack of an actual node
leads to terrible results: not only can we not form post-increment vld1_dup
instructions, but we form scalar pre-increment and post-increment
loads which force the loaded value into a GPR. This patch fixes that
by combining the vdup+load into an ARMISD node before DAGCombine
messes it up.

Also includes a crash fix for vld2_dup (see testcase @vld2dupi8_postinc_variable).

Differential Revision: https://reviews.llvm.org/D27694

llvm-svn: 289703

1 files changed, 144 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/ARM/vlddup.ll b/llvm/test/CodeGen/ARM/vlddup.ll
index c115a3863d0..66dcea81dd8 100644
--- a/llvm/test/CodeGen/ARM/vlddup.ll
+++ b/llvm/test/CodeGen/ARM/vlddup.ll
@@ -10,6 +10,84 @@ define <8 x i8> @vld1dupi8(i8* %A) nounwind {
         ret <8 x i8> %tmp3
 }
 
+define <8 x i8> @vld1dupi8_preinc(i8** noalias nocapture %a, i32 %b) nounwind {
+entry:
+;CHECK-LABEL: vld1dupi8_preinc:
+;CHECK: vld1.8 {d16[]}, [r1]
+  %0 = load i8*, i8** %a, align 4
+  %add.ptr = getelementptr inbounds i8, i8* %0, i32 %b
+  %1 = load i8, i8* %add.ptr, align 1
+  %2 = insertelement <8 x i8> undef, i8 %1, i32 0
+  %lane = shufflevector <8 x i8> %2, <8 x i8> undef, <8 x i32> zeroinitializer
+  store i8* %add.ptr, i8** %a, align 4
+  ret <8 x i8> %lane
+}
+
+define <8 x i8> @vld1dupi8_postinc_fixed(i8** noalias nocapture %a) nounwind {
+entry:
+;CHECK-LABEL: vld1dupi8_postinc_fixed:
+;CHECK: vld1.8 {d16[]}, [r1]!
+  %0 = load i8*, i8** %a, align 4
+  %1 = load i8, i8* %0, align 1
+  %2 = insertelement <8 x i8> undef, i8 %1, i32 0
+  %lane = shufflevector <8 x i8> %2, <8 x i8> undef, <8 x i32> zeroinitializer
+  %add.ptr = getelementptr inbounds i8, i8* %0, i32 1
+  store i8* %add.ptr, i8** %a, align 4
+  ret <8 x i8> %lane
+}
+
+define <8 x i8> @vld1dupi8_postinc_register(i8** noalias nocapture %a, i32 %n) nounwind {
+entry:
+;CHECK-LABEL: vld1dupi8_postinc_register:
+;CHECK: vld1.8 {d16[]}, [r2], r1
+  %0 = load i8*, i8** %a, align 4
+  %1 = load i8, i8* %0, align 1
+  %2 = insertelement <8 x i8> undef, i8 %1, i32 0
+  %lane = shufflevector <8 x i8> %2, <8 x i8> undef, <8 x i32> zeroinitializer
+  %add.ptr = getelementptr inbounds i8, i8* %0, i32 %n
+  store i8* %add.ptr, i8** %a, align 4
+  ret <8 x i8> %lane
+}
+
+define <16 x i8> @vld1dupqi8_preinc(i8** noalias nocapture %a, i32 %b) nounwind {
+entry:
+;CHECK-LABEL: vld1dupqi8_preinc:
+;CHECK: vld1.8 {d16[], d17[]}, [r1]
+  %0 = load i8*, i8** %a, align 4
+  %add.ptr = getelementptr inbounds i8, i8* %0, i32 %b
+  %1 = load i8, i8* %add.ptr, align 1
+  %2 = insertelement <16 x i8> undef, i8 %1, i32 0
+  %lane = shufflevector <16 x i8> %2, <16 x i8> undef, <16 x i32> zeroinitializer
+  store i8* %add.ptr, i8** %a, align 4
+  ret <16 x i8> %lane
+}
+
+define <16 x i8> @vld1dupqi8_postinc_fixed(i8** noalias nocapture %a) nounwind {
+entry:
+;CHECK-LABEL: vld1dupqi8_postinc_fixed:
+;CHECK: vld1.8 {d16[], d17[]}, [r1]!
+  %0 = load i8*, i8** %a, align 4
+  %1 = load i8, i8* %0, align 1
+  %2 = insertelement <16 x i8> undef, i8 %1, i32 0
+  %lane = shufflevector <16 x i8> %2, <16 x i8> undef, <16 x i32> zeroinitializer
+  %add.ptr = getelementptr inbounds i8, i8* %0, i32 1
+  store i8* %add.ptr, i8** %a, align 4
+  ret <16 x i8> %lane
+}
+
+define <16 x i8> @vld1dupqi8_postinc_register(i8** noalias nocapture %a, i32 %n) nounwind {
+entry:
+;CHECK-LABEL: vld1dupqi8_postinc_register:
+;CHECK: vld1.8 {d16[], d17[]}, [r2], r1
+  %0 = load i8*, i8** %a, align 4
+  %1 = load i8, i8* %0, align 1
+  %2 = insertelement <16 x i8> undef, i8 %1, i32 0
+  %lane = shufflevector <16 x i8> %2, <16 x i8> undef, <16 x i32> zeroinitializer
+  %add.ptr = getelementptr inbounds i8, i8* %0, i32 %n
+  store i8* %add.ptr, i8** %a, align 4
+  ret <16 x i8> %lane
+}
+
 define <4 x i16> @vld1dupi16(i16* %A) nounwind {
 ;CHECK-LABEL: vld1dupi16:
 ;Check the alignment value.  Max for this instruction is 16 bits:
@@ -20,6 +98,15 @@ define <4 x i16> @vld1dupi16(i16* %A) nounwind {
         ret <4 x i16> %tmp3
 }
 
+define <4 x i16> @vld1dupi16_misaligned(i16* %A) nounwind {
+;CHECK-LABEL: vld1dupi16_misaligned:
+;CHECK: vld1.16 {d16[]}, [r0]
+	%tmp1 = load i16, i16* %A, align 1
+	%tmp2 = insertelement <4 x i16> undef, i16 %tmp1, i32 0
+	%tmp3 = shufflevector <4 x i16> %tmp2, <4 x i16> undef, <4 x i32> zeroinitializer
+        ret <4 x i16> %tmp3
+}
+
 define <2 x i32> @vld1dupi32(i32* %A) nounwind {
 ;CHECK-LABEL: vld1dupi32:
 ;Check the alignment value.  Max for this instruction is 32 bits:
@@ -75,6 +162,63 @@ define <8 x i8> @vld2dupi8(i8* %A) nounwind {
         ret <8 x i8> %tmp5
 }
 
+define void @vld2dupi8_preinc(%struct.__neon_int8x8x2_t* noalias nocapture sret %agg.result, i8** noalias nocapture %a, i32 %b) nounwind {
+;CHECK-LABEL: vld2dupi8_preinc:
+;CHECK: vld2.8 {d16[], d17[]}, [r2]
+entry:
+  %0 = load i8*, i8** %a, align 4
+  %add.ptr = getelementptr inbounds i8, i8* %0, i32 %b
+  %vld_dup = tail call %struct.__neon_int8x8x2_t @llvm.arm.neon.vld2lane.v8i8.p0i8(i8* %add.ptr, <8 x i8> undef, <8 x i8> undef, i32 0, i32 1)
+  %1 = extractvalue %struct.__neon_int8x8x2_t %vld_dup, 0
+  %lane = shufflevector <8 x i8> %1, <8 x i8> undef, <8 x i32> zeroinitializer
+  %2 = extractvalue %struct.__neon_int8x8x2_t %vld_dup, 1
+  %lane1 = shufflevector <8 x i8> %2, <8 x i8> undef, <8 x i32> zeroinitializer
+  store i8* %add.ptr, i8** %a, align 4
+  %r8 = getelementptr inbounds %struct.__neon_int8x8x2_t, %struct.__neon_int8x8x2_t* %agg.result, i32 0, i32 0
+  store <8 x i8> %lane, <8 x i8>* %r8, align 8
+  %r11 = getelementptr inbounds %struct.__neon_int8x8x2_t, %struct.__neon_int8x8x2_t* %agg.result, i32 0, i32 1
+  store <8 x i8> %lane1, <8 x i8>* %r11, align 8
+  ret void
+}
+
+define void @vld2dupi8_postinc_fixed(%struct.__neon_int8x8x2_t* noalias nocapture sret %agg.result, i8** noalias nocapture %a) nounwind {
+entry:
+;CHECK-LABEL: vld2dupi8_postinc_fixed:
+;CHECK: vld2.8 {d16[], d17[]}, [r2]!
+  %0 = load i8*, i8** %a, align 4
+  %vld_dup = tail call %struct.__neon_int8x8x2_t @llvm.arm.neon.vld2lane.v8i8.p0i8(i8* %0, <8 x i8> undef, <8 x i8> undef, i32 0, i32 1)
+  %1 = extractvalue %struct.__neon_int8x8x2_t %vld_dup, 0
+  %lane = shufflevector <8 x i8> %1, <8 x i8> undef, <8 x i32> zeroinitializer
+  %2 = extractvalue %struct.__neon_int8x8x2_t %vld_dup, 1
+  %lane1 = shufflevector <8 x i8> %2, <8 x i8> undef, <8 x i32> zeroinitializer
+  %add.ptr = getelementptr inbounds i8, i8* %0, i32 2
+  store i8* %add.ptr, i8** %a, align 4
+  %r7 = getelementptr inbounds %struct.__neon_int8x8x2_t, %struct.__neon_int8x8x2_t* %agg.result, i32 0, i32 0
+  store <8 x i8> %lane, <8 x i8>* %r7, align 8
+  %r10 = getelementptr inbounds %struct.__neon_int8x8x2_t, %struct.__neon_int8x8x2_t* %agg.result, i32 0, i32 1
+  store <8 x i8> %lane1, <8 x i8>* %r10, align 8
+  ret void
+}
+
+define void @vld2dupi8_postinc_variable(%struct.__neon_int8x8x2_t* noalias nocapture sret %agg.result, i8** noalias nocapture %a, i32 %n) nounwind {
+entry:
+;CHECK-LABEL: vld2dupi8_postinc_variable:
+;CHECK: vld2.8 {d16[], d17[]}, [r3], r2
+  %0 = load i8*, i8** %a, align 4
+  %vld_dup = tail call %struct.__neon_int8x8x2_t @llvm.arm.neon.vld2lane.v8i8.p0i8(i8* %0, <8 x i8> undef, <8 x i8> undef, i32 0, i32 1)
+  %1 = extractvalue %struct.__neon_int8x8x2_t %vld_dup, 0
+  %lane = shufflevector <8 x i8> %1, <8 x i8> undef, <8 x i32> zeroinitializer
+  %2 = extractvalue %struct.__neon_int8x8x2_t %vld_dup, 1
+  %lane1 = shufflevector <8 x i8> %2, <8 x i8> undef, <8 x i32> zeroinitializer
+  %add.ptr = getelementptr inbounds i8, i8* %0, i32 %n
+  store i8* %add.ptr, i8** %a, align 4
+  %r7 = getelementptr inbounds %struct.__neon_int8x8x2_t, %struct.__neon_int8x8x2_t* %agg.result, i32 0, i32 0
+  store <8 x i8> %lane, <8 x i8>* %r7, align 8
+  %r10 = getelementptr inbounds %struct.__neon_int8x8x2_t, %struct.__neon_int8x8x2_t* %agg.result, i32 0, i32 1
+  store <8 x i8> %lane1, <8 x i8>* %r10, align 8
+  ret void
+}
+
 define <4 x i16> @vld2dupi16(i8* %A) nounwind {
 ;CHECK-LABEL: vld2dupi16:
 ;Check that a power-of-two alignment smaller than the total size of the memory