[CodeGen] Allow mempcy/memset to generate small overlapping stores.

Summary:
All targets either just return false here or properly model `Fast`, so I
don't think there is any reason to prevent CodeGen from doing the right
thing here.

Subscribers: nemanjai, javed.absar, eraman, jsji, llvm-commits

Differential Revision: https://reviews.llvm.org/D55365

llvm-svn: 348843

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 0136494..b9afcc1 100644 (file)
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -5395,12 +5395,10 @@ static bool FindOptimalMemOpLowering(std::vector<EVT> &MemOps,
 
       // If the new VT cannot cover all of the remaining bits, then consider
       // issuing a (or a pair of) unaligned and overlapping load / store.
-      // FIXME: Only does this for 64-bit or more since we don't have proper
-      // cost model for unaligned load / store.
       bool Fast;
-      if (NumMemOps && AllowOverlap &&
-          VTSize >= 8 && NewVTSize < Size &&
-          TLI.allowsMisalignedMemoryAccesses(VT, DstAS, DstAlign, &Fast) && Fast)
+      if (NumMemOps && AllowOverlap && NewVTSize < Size &&
+          TLI.allowsMisalignedMemoryAccesses(VT, DstAS, DstAlign, &Fast) &&
+          Fast)
         VTSize = Size;
       else {
         VT = NewVT;

diff --git a/llvm/test/CodeGen/AArch64/arm64-memcpy-inline.ll b/llvm/test/CodeGen/AArch64/arm64-memcpy-inline.ll
index 951076c..629cf37 100644 (file)
--- a/llvm/test/CodeGen/AArch64/arm64-memcpy-inline.ll
+++ b/llvm/test/CodeGen/AArch64/arm64-memcpy-inline.ll
@@ -16,10 +16,8 @@
 define i32 @t0() {
 entry:
 ; CHECK-LABEL: t0:
-; CHECK: ldrb [[REG0:w[0-9]+]], [x[[BASEREG:[0-9]+]], #10]
-; CHECK: strb [[REG0]], [x[[BASEREG2:[0-9]+]], #10]
-; CHECK: ldrh [[REG1:w[0-9]+]], [x[[BASEREG]], #8]
-; CHECK: strh [[REG1]], [x[[BASEREG2]], #8]
+; CHECK: ldur [[REG0:w[0-9]+]], [x[[BASEREG:[0-9]+]], #7]
+; CHECK: stur [[REG0]], [x[[BASEREG2:[0-9]+]], #7]
 ; CHECK: ldr [[REG2:x[0-9]+]],
 ; CHECK: str [[REG2]],
   call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 8 getelementptr inbounds (%struct.x, %struct.x* @dst, i32 0, i32 0), i8* align 8 getelementptr inbounds (%struct.x, %struct.x* @src, i32 0, i32 0), i32 11, i1 false)
@@ -74,9 +72,9 @@ entry:
 define void @t5(i8* nocapture %C) nounwind {
 entry:
 ; CHECK-LABEL: t5:
-; CHECK: strb wzr, [x0, #6]
-; CHECK: mov [[REG7:w[0-9]+]], #21587
-; CHECK: strh [[REG7]], [x0, #4]
+; CHECK: mov [[REG7:w[0-9]+]], #21337
+; CHECK: movk [[REG7]],
+; CHECK: stur [[REG7]], [x0, #3]
 ; CHECK: mov [[REG8:w[0-9]+]],
 ; CHECK: movk [[REG8]],
 ; CHECK: str [[REG8]], [x0]

diff --git a/llvm/test/CodeGen/PowerPC/jaggedstructs.ll b/llvm/test/CodeGen/PowerPC/jaggedstructs.ll
index 6128316..45e043a 100644 (file)
--- a/llvm/test/CodeGen/PowerPC/jaggedstructs.ll
+++ b/llvm/test/CodeGen/PowerPC/jaggedstructs.ll
@@ -34,11 +34,9 @@ entry:
 ; CHECK-DAG: lwz {{[0-9]+}}, 178(1)
 ; CHECK-DAG: sth {{[0-9]+}}, 70(1)
 ; CHECK-DAG: stw {{[0-9]+}}, 66(1)
-; CHECK-DAG: lbz {{[0-9]+}}, 191(1)
-; CHECK-DAG: lhz {{[0-9]+}}, 189(1)
+; CHECK-DAG: lwz {{[0-9]+}}, 188(1)
 ; CHECK-DAG: lwz {{[0-9]+}}, 185(1)
-; CHECK-DAG: stb {{[0-9]+}}, 79(1)
-; CHECK-DAG: sth {{[0-9]+}}, 77(1)
+; CHECK-DAG: stw {{[0-9]+}}, 76(1)
 ; CHECK-DAG: stw {{[0-9]+}}, 73(1)
 ; CHECK-DAG: ld 6, 72(1)
 ; CHECK-DAG: ld 5, 64(1)

diff --git a/llvm/test/CodeGen/PowerPC/structsinmem.ll b/llvm/test/CodeGen/PowerPC/structsinmem.ll
index c8ea3be..bbe8289 100644 (file)
--- a/llvm/test/CodeGen/PowerPC/structsinmem.ll
+++ b/llvm/test/CodeGen/PowerPC/structsinmem.ll
@@ -157,8 +157,7 @@ entry:
 ; CHECK: stw {{[0-9]+}}, 147(1)
 ; CHECK: sth {{[0-9]+}}, 158(1)
 ; CHECK: stw {{[0-9]+}}, 154(1)
-; CHECK: stb {{[0-9]+}}, 167(1)
-; CHECK: sth {{[0-9]+}}, 165(1)
+; CHECK: stw {{[0-9]+}}, 164(1)
 ; CHECK: stw {{[0-9]+}}, 161(1)
 }
 

diff --git a/llvm/test/CodeGen/PowerPC/structsinregs.ll b/llvm/test/CodeGen/PowerPC/structsinregs.ll
index d8afc8f..52976ca 100644 (file)
--- a/llvm/test/CodeGen/PowerPC/structsinregs.ll
+++ b/llvm/test/CodeGen/PowerPC/structsinregs.ll
@@ -148,8 +148,7 @@ entry:
 ; CHECK: stw {{[0-9]+}}, 83(1)
 ; CHECK: sth {{[0-9]+}}, 94(1)
 ; CHECK: stw {{[0-9]+}}, 90(1)
-; CHECK: stb {{[0-9]+}}, 103(1)
-; CHECK: sth {{[0-9]+}}, 101(1)
+; CHECK: stw {{[0-9]+}}, 100(1)
 ; CHECK: stw {{[0-9]+}}, 97(1)
 ; CHECK: ld 9, 96(1)
 ; CHECK: ld 8, 88(1)

diff --git a/llvm/test/CodeGen/X86/memcpy-from-string.ll b/llvm/test/CodeGen/X86/memcpy-from-string.ll
index 4546672..af88ffa 100644 (file)
--- a/llvm/test/CodeGen/X86/memcpy-from-string.ll
+++ b/llvm/test/CodeGen/X86/memcpy-from-string.ll
@@ -16,8 +16,7 @@ target triple = "x86_64-unknown-linux-gnu"
 define void @foo(i8* %tmp2) {
 ; X86-LABEL: foo:
 ; X86:       # %bb.0:
-; X86-NEXT:    movb $0, 6(%rdi)
-; X86-NEXT:    movw $15212, 4(%rdi) # imm = 0x3B6C
+; X86-NEXT:    movl $3894379, 3(%rdi) # imm = 0x3B6C6B
 ; X86-NEXT:    movl $1802117222, (%rdi) # imm = 0x6B6A2066
 ; X86-NEXT:    retq
   call void @llvm.memcpy.p0i8.p0i8.i64(i8* %tmp2, i8* getelementptr inbounds ([10 x i8], [10 x i8]* @0, i64 0, i64 3), i64 7, i1 false)

diff --git a/llvm/test/CodeGen/X86/memset-2.ll b/llvm/test/CodeGen/X86/memset-2.ll
index 33a2227..0b91628 100644 (file)
--- a/llvm/test/CodeGen/X86/memset-2.ll
+++ b/llvm/test/CodeGen/X86/memset-2.ll
@@ -51,11 +51,10 @@ define void @t4(i8* nocapture %s, i8 %a) nounwind {
 ; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax
 ; CHECK-NEXT:    movzbl {{[0-9]+}}(%esp), %ecx
 ; CHECK-NEXT:    imull $16843009, %ecx, %ecx ## imm = 0x1010101
+; CHECK-NEXT:    movl %ecx, 11(%eax)
 ; CHECK-NEXT:    movl %ecx, 8(%eax)
 ; CHECK-NEXT:    movl %ecx, 4(%eax)
 ; CHECK-NEXT:    movl %ecx, (%eax)
-; CHECK-NEXT:    movw %cx, 12(%eax)
-; CHECK-NEXT:    movb %cl, 14(%eax)
 ; CHECK-NEXT:    retl
 entry:
   tail call void @llvm.memset.p0i8.i32(i8* %s, i8 %a, i32 15, i1 false)

diff --git a/llvm/test/CodeGen/X86/memset-zero.ll b/llvm/test/CodeGen/X86/memset-zero.ll
index 220968d..f2f0d07 100644 (file)
--- a/llvm/test/CodeGen/X86/memset-zero.ll
+++ b/llvm/test/CodeGen/X86/memset-zero.ll
@@ -71,22 +71,19 @@ define void @memset_7(i8* %a) nounwind  {
 ; X86-LABEL: memset_7:
 ; X86:       # %bb.0: # %entry
 ; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT:    movb $0, 6(%eax)
-; X86-NEXT:    movw $0, 4(%eax)
+; X86-NEXT:    movl $0, 3(%eax)
 ; X86-NEXT:    movl $0, (%eax)
 ; X86-NEXT:    retl
 ;
 ; CORE2-LABEL: memset_7:
 ; CORE2:       # %bb.0: # %entry
-; CORE2-NEXT:    movb $0, 6(%rdi)
-; CORE2-NEXT:    movw $0, 4(%rdi)
+; CORE2-NEXT:    movl $0, 3(%rdi)
 ; CORE2-NEXT:    movl $0, (%rdi)
 ; CORE2-NEXT:    retq
 ;
 ; NEHALEM-LABEL: memset_7:
 ; NEHALEM:       # %bb.0: # %entry
-; NEHALEM-NEXT:    movb $0, 6(%rdi)
-; NEHALEM-NEXT:    movw $0, 4(%rdi)
+; NEHALEM-NEXT:    movl $0, 3(%rdi)
 ; NEHALEM-NEXT:    movl $0, (%rdi)
 ; NEHALEM-NEXT:    retq
 entry:
@@ -120,23 +117,20 @@ define void @memset_11(i8* %a) nounwind  {
 ; X86-LABEL: memset_11:
 ; X86:       # %bb.0: # %entry
 ; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT:    movb $0, 10(%eax)
-; X86-NEXT:    movw $0, 8(%eax)
+; X86-NEXT:    movl $0, 7(%eax)
 ; X86-NEXT:    movl $0, 4(%eax)
 ; X86-NEXT:    movl $0, (%eax)
 ; X86-NEXT:    retl
 ;
 ; CORE2-LABEL: memset_11:
 ; CORE2:       # %bb.0: # %entry
-; CORE2-NEXT:    movb $0, 10(%rdi)
-; CORE2-NEXT:    movw $0, 8(%rdi)
+; CORE2-NEXT:    movl $0, 7(%rdi)
 ; CORE2-NEXT:    movq $0, (%rdi)
 ; CORE2-NEXT:    retq
 ;
 ; NEHALEM-LABEL: memset_11:
 ; NEHALEM:       # %bb.0: # %entry
-; NEHALEM-NEXT:    movb $0, 10(%rdi)
-; NEHALEM-NEXT:    movw $0, 8(%rdi)
+; NEHALEM-NEXT:    movl $0, 7(%rdi)
 ; NEHALEM-NEXT:    movq $0, (%rdi)
 ; NEHALEM-NEXT:    retq
 entry:
@@ -174,8 +168,7 @@ define void @memset_15(i8* %a) nounwind  {
 ; X86-LABEL: memset_15:
 ; X86:       # %bb.0: # %entry
 ; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT:    movb $0, 14(%eax)
-; X86-NEXT:    movw $0, 12(%eax)
+; X86-NEXT:    movl $0, 11(%eax)
 ; X86-NEXT:    movl $0, 8(%eax)
 ; X86-NEXT:    movl $0, 4(%eax)
 ; X86-NEXT:    movl $0, (%eax)
@@ -256,8 +249,7 @@ define void @memset_19(i8* %a) nounwind  {
 ; X86-LABEL: memset_19:
 ; X86:       # %bb.0: # %entry
 ; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT:    movb $0, 18(%eax)
-; X86-NEXT:    movw $0, 16(%eax)
+; X86-NEXT:    movl $0, 15(%eax)
 ; X86-NEXT:    movl $0, 12(%eax)
 ; X86-NEXT:    movl $0, 8(%eax)
 ; X86-NEXT:    movl $0, 4(%eax)
@@ -266,8 +258,7 @@ define void @memset_19(i8* %a) nounwind  {
 ;
 ; CORE2-LABEL: memset_19:
 ; CORE2:       # %bb.0: # %entry
-; CORE2-NEXT:    movb $0, 18(%rdi)
-; CORE2-NEXT:    movw $0, 16(%rdi)
+; CORE2-NEXT:    movl $0, 15(%rdi)
 ; CORE2-NEXT:    movq $0, 8(%rdi)
 ; CORE2-NEXT:    movq $0, (%rdi)
 ; CORE2-NEXT:    retq
@@ -276,8 +267,7 @@ define void @memset_19(i8* %a) nounwind  {
 ; NEHALEM:       # %bb.0: # %entry
 ; NEHALEM-NEXT:    xorps %xmm0, %xmm0
 ; NEHALEM-NEXT:    movups %xmm0, (%rdi)
-; NEHALEM-NEXT:    movb $0, 18(%rdi)
-; NEHALEM-NEXT:    movw $0, 16(%rdi)
+; NEHALEM-NEXT:    movl $0, 15(%rdi)
 ; NEHALEM-NEXT:    retq
 entry:
        call void @llvm.memset.p0i8.i64(i8* %a, i8 0, i64 19, i1 false)
@@ -288,8 +278,7 @@ define void @memset_31(i8* %a) nounwind  {
 ; X86-LABEL: memset_31:
 ; X86:       # %bb.0: # %entry
 ; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT:    movb $0, 30(%eax)
-; X86-NEXT:    movw $0, 28(%eax)
+; X86-NEXT:    movl $0, 27(%eax)
 ; X86-NEXT:    movl $0, 24(%eax)
 ; X86-NEXT:    movl $0, 20(%eax)
 ; X86-NEXT:    movl $0, 16(%eax)
@@ -322,8 +311,7 @@ define void @memset_35(i8* %a) nounwind  {
 ; X86-LABEL: memset_35:
 ; X86:       # %bb.0: # %entry
 ; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT:    movb $0, 34(%eax)
-; X86-NEXT:    movw $0, 32(%eax)
+; X86-NEXT:    movl $0, 31(%eax)
 ; X86-NEXT:    movl $0, 28(%eax)
 ; X86-NEXT:    movl $0, 24(%eax)
 ; X86-NEXT:    movl $0, 20(%eax)
@@ -336,8 +324,7 @@ define void @memset_35(i8* %a) nounwind  {
 ;
 ; CORE2-LABEL: memset_35:
 ; CORE2:       # %bb.0: # %entry
-; CORE2-NEXT:    movb $0, 34(%rdi)
-; CORE2-NEXT:    movw $0, 32(%rdi)
+; CORE2-NEXT:    movl $0, 31(%rdi)
 ; CORE2-NEXT:    movq $0, 24(%rdi)
 ; CORE2-NEXT:    movq $0, 16(%rdi)
 ; CORE2-NEXT:    movq $0, 8(%rdi)
@@ -349,8 +336,7 @@ define void @memset_35(i8* %a) nounwind  {
 ; NEHALEM-NEXT:    xorps %xmm0, %xmm0
 ; NEHALEM-NEXT:    movups %xmm0, 16(%rdi)
 ; NEHALEM-NEXT:    movups %xmm0, (%rdi)
-; NEHALEM-NEXT:    movb $0, 34(%rdi)
-; NEHALEM-NEXT:    movw $0, 32(%rdi)
+; NEHALEM-NEXT:    movl $0, 31(%rdi)
 ; NEHALEM-NEXT:    retq
 entry:
        call void @llvm.memset.p0i8.i64(i8* %a, i8 0, i64 35, i1 false)

diff --git a/llvm/test/CodeGen/X86/unaligned-load.ll b/llvm/test/CodeGen/X86/unaligned-load.ll
index 980fca2..be8ca01 100644 (file)
--- a/llvm/test/CodeGen/X86/unaligned-load.ll
+++ b/llvm/test/CodeGen/X86/unaligned-load.ll
@@ -6,21 +6,23 @@
 @.str1 = internal constant [31 x i8] c"DHRYSTONE PROGRAM, SOME STRING\00", align 8
 @.str3 = internal constant [31 x i8] c"DHRYSTONE PROGRAM, 2'ND STRING\00", align 8
 
+; This can be improved; see PR39952.
+
 define void @func() nounwind ssp {
 ; I386-LABEL: func:
 ; I386:       ## %bb.0: ## %entry
-; I386-NEXT:    pushl %esi
-; I386-NEXT:    subl $40, %esp
-; I386-NEXT:    leal {{[0-9]+}}(%esp), %esi
+; I386-NEXT:    subl $32, %esp
 ; I386-NEXT:    .p2align 4, 0x90
 ; I386-NEXT:  LBB0_1: ## %bb
 ; I386-NEXT:    ## =>This Inner Loop Header: Depth=1
-; I386-NEXT:    subl $4, %esp
-; I386-NEXT:    pushl $31
-; I386-NEXT:    pushl $_.str3
-; I386-NEXT:    pushl %esi
-; I386-NEXT:    calll _memcpy
-; I386-NEXT:    addl $16, %esp
+; I386-NEXT:    movl $4673097, {{[0-9]+}}(%esp) ## imm = 0x474E49
+; I386-NEXT:    movl $1230132307, {{[0-9]+}}(%esp) ## imm = 0x49525453
+; I386-NEXT:    movl $541347367, {{[0-9]+}}(%esp) ## imm = 0x20444E27
+; I386-NEXT:    movl $840969293, {{[0-9]+}}(%esp) ## imm = 0x32202C4D
+; I386-NEXT:    movl $1095911247, {{[0-9]+}}(%esp) ## imm = 0x4152474F
+; I386-NEXT:    movl $1380982853, {{[0-9]+}}(%esp) ## imm = 0x52502045
+; I386-NEXT:    movl $1313821779, {{[0-9]+}}(%esp) ## imm = 0x4E4F5453
+; I386-NEXT:    movl $1498564676, (%esp) ## imm = 0x59524844
 ; I386-NEXT:    jmp LBB0_1
 ;
 ; CORE2-LABEL: func:
@@ -61,4 +63,57 @@ return:                                           ; No predecessors!
   ret void
 }
 
+define void @func_aligned() nounwind ssp {
+; I386-LABEL: func_aligned:
+; I386:       ## %bb.0: ## %entry
+; I386-NEXT:    subl $44, %esp
+; I386-NEXT:    movaps {{.*#+}} xmm0 = [1498564676,1313821779,1380982853,1095911247]
+; I386-NEXT:    .p2align 4, 0x90
+; I386-NEXT:  LBB1_1: ## %bb
+; I386-NEXT:    ## =>This Inner Loop Header: Depth=1
+; I386-NEXT:    movaps %xmm0, (%esp)
+; I386-NEXT:    movl $4673097, {{[0-9]+}}(%esp) ## imm = 0x474E49
+; I386-NEXT:    movl $1230132307, {{[0-9]+}}(%esp) ## imm = 0x49525453
+; I386-NEXT:    movl $541347367, {{[0-9]+}}(%esp) ## imm = 0x20444E27
+; I386-NEXT:    movl $840969293, {{[0-9]+}}(%esp) ## imm = 0x32202C4D
+; I386-NEXT:    jmp LBB1_1
+;
+; CORE2-LABEL: func_aligned:
+; CORE2:       ## %bb.0: ## %entry
+; CORE2-NEXT:    movabsq $20070800167293728, %rax ## imm = 0x474E4952545320
+; CORE2-NEXT:    movabsq $2325069237881678925, %rcx ## imm = 0x20444E2732202C4D
+; CORE2-NEXT:    movabsq $4706902966564560965, %rdx ## imm = 0x4152474F52502045
+; CORE2-NEXT:    movabsq $5642821575076104260, %rsi ## imm = 0x4E4F545359524844
+; CORE2-NEXT:    .p2align 4, 0x90
+; CORE2-NEXT:  LBB1_1: ## %bb
+; CORE2-NEXT:    ## =>This Inner Loop Header: Depth=1
+; CORE2-NEXT:    movq %rax, -{{[0-9]+}}(%rsp)
+; CORE2-NEXT:    movq %rcx, -{{[0-9]+}}(%rsp)
+; CORE2-NEXT:    movq %rdx, -{{[0-9]+}}(%rsp)
+; CORE2-NEXT:    movq %rsi, -{{[0-9]+}}(%rsp)
+; CORE2-NEXT:    jmp LBB1_1
+;
+; COREI7-LABEL: func_aligned:
+; COREI7:       ## %bb.0: ## %entry
+; COREI7-NEXT:    movups _.str3+{{.*}}(%rip), %xmm0
+; COREI7-NEXT:    movups {{.*}}(%rip), %xmm1
+; COREI7-NEXT:    .p2align 4, 0x90
+; COREI7-NEXT:  LBB1_1: ## %bb
+; COREI7-NEXT:    ## =>This Inner Loop Header: Depth=1
+; COREI7-NEXT:    movups %xmm0, -{{[0-9]+}}(%rsp)
+; COREI7-NEXT:    movaps %xmm1, -{{[0-9]+}}(%rsp)
+; COREI7-NEXT:    jmp LBB1_1
+entry:
+  %String2Loc = alloca [31 x i8], align 16
+  br label %bb
+
+bb:                                               ; preds = %bb, %entry
+  %String2Loc9 = getelementptr inbounds [31 x i8], [31 x i8]* %String2Loc, i64 0, i64 0
+  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %String2Loc9, i8* getelementptr inbounds ([31 x i8], [31 x i8]* @.str3, i64 0, i64 0), i64 31, i1 false)
+  br label %bb
+
+return:                                           ; No predecessors!
+  ret void
+}
+
 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i1) nounwind