DAGCombiner: Replace store of FP constant after attemping store merges

If storing multiple FP constants, some subset of the stores
would be replaced with integers due to visit order, so
MergeConsecutiveStores would only partially merge
these.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248169 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 5c4110276cd9c150e9b3df159525180ccee8ca0c..24627bcfcad40134facc5821760cbd170191cca4 100644 (file)
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -11485,16 +11485,6 @@ SDValue DAGCombiner::visitSTORE(SDNode *N) {
   if (Value.getOpcode() == ISD::UNDEF && ST->isUnindexed())
     return Chain;
 
-  // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
-  //
-  // Make sure to do this only after attempting to merge stores in order to
-  //  avoid changing the types of some subset of stores due to visit order,
-  //  preventing their merging.
-  if (isa<ConstantFPSDNode>(Value)) {
-    if (SDValue NewSt = replaceStoreOfFPConstant(ST))
-      return NewSt;
-  }
-
   // Try to infer better alignment information than the store already has.
   if (OptLevel != CodeGenOpt::None && ST->isUnindexed()) {
     if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
@@ -11618,6 +11608,16 @@ SDValue DAGCombiner::visitSTORE(SDNode *N) {
       return SDValue(N, 0);
   }
 
+  // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
+  //
+  // Make sure to do this only after attempting to merge stores in order to
+  //  avoid changing the types of some subset of stores due to visit order,
+  //  preventing their merging.
+  if (isa<ConstantFPSDNode>(Value)) {
+    if (SDValue NewSt = replaceStoreOfFPConstant(ST))
+      return NewSt;
+  }
+
   return ReduceLoadOpStoreWidth(N);
 }
 

diff --git a/test/CodeGen/AMDGPU/merge-stores.ll b/test/CodeGen/AMDGPU/merge-stores.ll
index 87148ae9f69c5fa8cc4efedc53a6f124ed258137..62d372a398aa668c56bd0bbbaa5bd1da7a69aa0c 100644 (file)
--- a/test/CodeGen/AMDGPU/merge-stores.ll
+++ b/test/CodeGen/AMDGPU/merge-stores.ll
@@ -121,10 +121,7 @@ define void @merge_global_store_4_constants_i32(i32 addrspace(1)* %out) #0 {
 }
 
 ; GCN-LABEL: {{^}}merge_global_store_4_constants_f32_order:
-; XGCN: buffer_store_dwordx4
-; GCN: buffer_store_dword v
-; GCN: buffer_store_dword v
-; GCN: buffer_store_dwordx2 v
+; GCN: buffer_store_dwordx4
 define void @merge_global_store_4_constants_f32_order(float addrspace(1)* %out) #0 {
   %out.gep.1 = getelementptr float, float addrspace(1)* %out, i32 1
   %out.gep.2 = getelementptr float, float addrspace(1)* %out, i32 2
@@ -137,17 +134,9 @@ define void @merge_global_store_4_constants_f32_order(float addrspace(1)* %out)
   ret void
 }
 
-; First store is out of order. Because of order of combines, the
-; consecutive store fails because only some of the stores have been
-; replaced with integer constant stores, and then won't merge because
-; the types are different.
-
+; First store is out of order.
 ; GCN-LABEL: {{^}}merge_global_store_4_constants_f32:
-; XGCN: buffer_store_dwordx4
-; GCN: buffer_store_dword v
-; GCN: buffer_store_dword v
-; GCN: buffer_store_dword v
-; GCN: buffer_store_dword v
+; GCN: buffer_store_dwordx4
 define void @merge_global_store_4_constants_f32(float addrspace(1)* %out) #0 {
   %out.gep.1 = getelementptr float, float addrspace(1)* %out, i32 1
   %out.gep.2 = getelementptr float, float addrspace(1)* %out, i32 2
@@ -160,6 +149,29 @@ define void @merge_global_store_4_constants_f32(float addrspace(1)* %out) #0 {
   ret void
 }
 
+; FIXME: Should be able to merge this
+; GCN-LABEL: {{^}}merge_global_store_4_constants_mixed_i32_f32:
+; XGCN: buffer_store_dwordx4
+; GCN: buffer_store_dword
+; GCN: buffer_store_dword
+; GCN: buffer_store_dword
+; GCN: buffer_store_dword
+; GCN: s_endpgm
+define void @merge_global_store_4_constants_mixed_i32_f32(float addrspace(1)* %out) #0 {
+  %out.gep.1 = getelementptr float, float addrspace(1)* %out, i32 1
+  %out.gep.2 = getelementptr float, float addrspace(1)* %out, i32 2
+  %out.gep.3 = getelementptr float, float addrspace(1)* %out, i32 3
+
+  %out.gep.1.bc = bitcast float addrspace(1)* %out.gep.1 to i32 addrspace(1)*
+  %out.gep.3.bc = bitcast float addrspace(1)* %out.gep.3 to i32 addrspace(1)*
+
+  store i32 11, i32 addrspace(1)* %out.gep.1.bc
+  store float 2.0, float addrspace(1)* %out.gep.2
+  store i32 17, i32 addrspace(1)* %out.gep.3.bc
+  store float 8.0, float addrspace(1)* %out
+  ret void
+}
+
 ; GCN-LABEL: {{^}}merge_global_store_3_constants_i32:
 ; SI-DAG: buffer_store_dwordx2
 ; SI-DAG: buffer_store_dword

diff --git a/test/CodeGen/PowerPC/vector-merge-store-fp-constants.ll b/test/CodeGen/PowerPC/vector-merge-store-fp-constants.ll
new file mode 100644 (file)
index 0000000..db92f20
--- /dev/null
+++ b/test/CodeGen/PowerPC/vector-merge-store-fp-constants.ll
@@ -0,0 +1,28 @@
+; RUN: llc -march=ppc64 -mtriple=ppc64-apple-darwin < %s | FileCheck %s
+
+; CHECK-LABEL: {{^}}_merge_8_float_zero_stores:
+; CHECK: li [[ZEROREG:r[0-9]+]], 0
+; CHECK-DAG: std [[ZEROREG]], 0([[PTR:r[0-9]+]])
+; CHECK-DAG: std [[ZEROREG]], 8([[PTR]])
+; CHECK-DAG: std [[ZEROREG]], 16([[PTR]])
+; CHECK-DAG: std [[ZEROREG]], 24([[PTR]])
+; CHECK: blr
+define void @merge_8_float_zero_stores(float* %ptr) {
+  %idx0 = getelementptr float, float* %ptr, i64 0
+  %idx1 = getelementptr float, float* %ptr, i64 1
+  %idx2 = getelementptr float, float* %ptr, i64 2
+  %idx3 = getelementptr float, float* %ptr, i64 3
+  %idx4 = getelementptr float, float* %ptr, i64 4
+  %idx5 = getelementptr float, float* %ptr, i64 5
+  %idx6 = getelementptr float, float* %ptr, i64 6
+  %idx7 = getelementptr float, float* %ptr, i64 7
+  store float 0.0, float* %idx0, align 4
+  store float 0.0, float* %idx1, align 4
+  store float 0.0, float* %idx2, align 4
+  store float 0.0, float* %idx3, align 4
+  store float 0.0, float* %idx4, align 4
+  store float 0.0, float* %idx5, align 4
+  store float 0.0, float* %idx6, align 4
+  store float 0.0, float* %idx7, align 4
+  ret void
+}

diff --git a/test/CodeGen/X86/vector-merge-store-fp-constants.ll b/test/CodeGen/X86/vector-merge-store-fp-constants.ll
new file mode 100644 (file)
index 0000000..a6fb32d
--- /dev/null
+++ b/test/CodeGen/X86/vector-merge-store-fp-constants.ll
@@ -0,0 +1,35 @@
+; RUN: llc -march=x86-64 -mtriple=x86_64-unknown-unknown < %s | FileCheck -check-prefix=DEFAULTCPU -check-prefix=ALL %s
+; RUN: llc -march=x86-64 -mcpu=x86-64 -mtriple=x86_64-unknown-unknown < %s | FileCheck -check-prefix=X8664CPU -check-prefix=ALL %s
+
+
+; ALL-LABEL: {{^}}merge_8_float_zero_stores:
+
+; DEFAULTCPU-DAG: movq $0, ([[PTR:%[a-z]+]])
+; DEFAULTCPU-DAG: movq $0, 8([[PTR]])
+; DEFAULTCPU-DAG: movq $0, 16([[PTR]])
+; DEFAULTCPU-DAG: movq $0, 24([[PTR]])
+
+; X8664CPU: xorps [[ZEROREG:%xmm[0-9]+]], [[ZEROREG]]
+; X8664CPU-DAG: movups [[ZEROREG]], ([[PTR:%[a-z]+]])
+; X8664CPU-DAG: movups [[ZEROREG]], 16([[PTR:%[a-z]+]])
+
+; ALL: retq
+define void @merge_8_float_zero_stores(float* %ptr) {
+  %idx0 = getelementptr float, float* %ptr, i64 0
+  %idx1 = getelementptr float, float* %ptr, i64 1
+  %idx2 = getelementptr float, float* %ptr, i64 2
+  %idx3 = getelementptr float, float* %ptr, i64 3
+  %idx4 = getelementptr float, float* %ptr, i64 4
+  %idx5 = getelementptr float, float* %ptr, i64 5
+  %idx6 = getelementptr float, float* %ptr, i64 6
+  %idx7 = getelementptr float, float* %ptr, i64 7
+  store float 0.0, float* %idx0, align 4
+  store float 0.0, float* %idx1, align 4
+  store float 0.0, float* %idx2, align 4
+  store float 0.0, float* %idx3, align 4
+  store float 0.0, float* %idx4, align 4
+  store float 0.0, float* %idx5, align 4
+  store float 0.0, float* %idx6, align 4
+  store float 0.0, float* %idx7, align 4
+  ret void
+}