[DAGCombiner] Add bswap(logic_op(bswap(x), y)) regression test case; NFC

Fold the following case on SelectionDAG combiner
This patch includes the regression test cases

```
bswap(logic_op(x, bswap(y))) -> logic_op(bswap(x), y)
bswap(logic_op(bswap(x), y)) -> logic_op(x, bswap(y))
bswap(logic_op(bswap(x), bswap(y))) -> logic_op(x, y) (with multiuse)
```

Reviewed By: goldstein.w.n

Differential Revision: https://reviews.llvm.org/D149782

llvm/test/CodeGen/ARM/combine-bitreverse.ll

@@ -0,0 +1,112 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=thumbv7m-none-eabi -mattr=v7 | FileCheck %s --check-prefixes=CHECK
+
+declare i16 @llvm.bswap.i16(i16) readnone
+declare i32 @llvm.bswap.i32(i32) readnone
+declare i32 @llvm.bitreverse.i32(i32) readnone
+
+define i32 @brev_and_lhs_brev32(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: brev_and_lhs_brev32:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    rbit r0, r0
+; CHECK-NEXT:    ands r0, r1
+; CHECK-NEXT:    rbit r0, r0
+; CHECK-NEXT:    bx lr
+  %1 = tail call i32 @llvm.bitreverse.i32(i32 %a)
+  %2 = and i32 %1, %b
+  %3 = tail call i32 @llvm.bitreverse.i32(i32 %2)
+  ret i32 %3
+}
+
+define i32 @brev_or_lhs_brev32(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: brev_or_lhs_brev32:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    rbit r0, r0
+; CHECK-NEXT:    orrs r0, r1
+; CHECK-NEXT:    rbit r0, r0
+; CHECK-NEXT:    bx lr
+  %1 = tail call i32 @llvm.bitreverse.i32(i32 %a)
+  %2 = or i32 %1, %b
+  %3 = tail call i32 @llvm.bitreverse.i32(i32 %2)
+  ret i32 %3
+}
+
+define i32 @brev_xor_rhs_brev32(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: brev_xor_rhs_brev32:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    rbit r1, r1
+; CHECK-NEXT:    eors r0, r1
+; CHECK-NEXT:    rbit r0, r0
+; CHECK-NEXT:    bx lr
+  %1 = tail call i32 @llvm.bitreverse.i32(i32 %b)
+  %2 = xor i32 %a, %1
+  %3 = tail call i32 @llvm.bitreverse.i32(i32 %2)
+  ret i32 %3
+}
+
+define i32 @brev_and_all_operand_multiuse(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: brev_and_all_operand_multiuse:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    rbit r1, r1
+; CHECK-NEXT:    rbit r0, r0
+; CHECK-NEXT:    and.w r2, r0, r1
+; CHECK-NEXT:    rbit r2, r2
+; CHECK-NEXT:    muls r0, r2, r0
+; CHECK-NEXT:    muls r0, r1, r0
+; CHECK-NEXT:    bx lr
+  %1 = tail call i32 @llvm.bitreverse.i32(i32 %a)
+  %2 = tail call i32 @llvm.bitreverse.i32(i32 %b)
+  %3 = and i32 %1, %2
+  %4 = tail call i32 @llvm.bitreverse.i32(i32 %3)
+  %5 = mul i32 %1, %4 ;increase use of left bitreverse
+  %6 = mul i32 %2, %5 ;increase use of right bitreverse
+
+  ret i32 %6
+}
+
+; negative test
+define i32 @brev_and_rhs_brev32_multiuse1(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: brev_and_rhs_brev32_multiuse1:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    rbit r1, r1
+; CHECK-NEXT:    ands r0, r1
+; CHECK-NEXT:    rbit r1, r0
+; CHECK-NEXT:    muls r0, r1, r0
+; CHECK-NEXT:    bx lr
+  %1 = tail call i32 @llvm.bitreverse.i32(i32 %b)
+  %2 = and i32 %1, %a
+  %3 = tail call i32 @llvm.bitreverse.i32(i32 %2)
+  %4 = mul i32 %2, %3 ;increase use of logical op
+  ret i32 %4
+}
+
+; negative test
+define i32 @brev_and_rhs_brev32_multiuse2(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: brev_and_rhs_brev32_multiuse2:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    rbit r1, r1
+; CHECK-NEXT:    ands r0, r1
+; CHECK-NEXT:    rbit r0, r0
+; CHECK-NEXT:    muls r0, r1, r0
+; CHECK-NEXT:    bx lr
+  %1 = tail call i32 @llvm.bitreverse.i32(i32 %b)
+  %2 = and i32 %1, %a
+  %3 = tail call i32 @llvm.bitreverse.i32(i32 %2)
+  %4 = mul i32 %1, %3 ;increase use of inner bitreverse
+  ret i32 %4
+}
+
+; negative test
+define i32 @brev_xor_rhs_bs32(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: brev_xor_rhs_bs32:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    rev r1, r1
+; CHECK-NEXT:    eors r0, r1
+; CHECK-NEXT:    rbit r0, r0
+; CHECK-NEXT:    bx lr
+  %1 = tail call i32 @llvm.bswap.i32(i32 %b)
+  %2 = xor i32 %a, %1
+  %3 = tail call i32 @llvm.bitreverse.i32(i32 %2)
+  ret i32 %3
+}
+

llvm/test/CodeGen/ARM/combine-bswap.ll

@@ -0,0 +1,87 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=thumbv7m-none-eabi -mattr=v7 | FileCheck %s --check-prefixes=CHECK
+
+declare i32 @llvm.bswap.i32(i32) readnone
+declare i64 @llvm.bswap.i64(i64) readnone
+declare i32 @llvm.bitreverse.i32(i32) readnone
+
+define i32 @bs_and_lhs_bs32(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: bs_and_lhs_bs32:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    rev r0, r0
+; CHECK-NEXT:    ands r0, r1
+; CHECK-NEXT:    rev r0, r0
+; CHECK-NEXT:    bx lr
+  %1 = tail call i32 @llvm.bswap.i32(i32 %a)
+  %2 = and i32 %1, %b
+  %3 = tail call i32 @llvm.bswap.i32(i32 %2)
+  ret i32 %3
+}
+
+define i64 @bs_or_rhs_bs64(i64 %a, i64 %b) #0 {
+; CHECK-LABEL: bs_or_rhs_bs64:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    rev r2, r2
+; CHECK-NEXT:    orrs r1, r2
+; CHECK-NEXT:    rev r2, r1
+; CHECK-NEXT:    rev r1, r3
+; CHECK-NEXT:    orrs r0, r1
+; CHECK-NEXT:    rev r1, r0
+; CHECK-NEXT:    mov r0, r2
+; CHECK-NEXT:    bx lr
+  %1 = tail call i64 @llvm.bswap.i64(i64 %b)
+  %2 = or i64 %a, %1
+  %3 = tail call i64 @llvm.bswap.i64(i64 %2)
+  ret i64 %3
+}
+
+define i32 @bs_and_all_operand_multiuse(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: bs_and_all_operand_multiuse:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    rev r1, r1
+; CHECK-NEXT:    rev r0, r0
+; CHECK-NEXT:    and.w r2, r0, r1
+; CHECK-NEXT:    rev r2, r2
+; CHECK-NEXT:    muls r0, r2, r0
+; CHECK-NEXT:    muls r0, r1, r0
+; CHECK-NEXT:    bx lr
+  %1 = tail call i32 @llvm.bswap.i32(i32 %a)
+  %2 = tail call i32 @llvm.bswap.i32(i32 %b)
+  %3 = and i32 %1, %2
+  %4 = tail call i32 @llvm.bswap.i32(i32 %3)
+  %5 = mul i32 %1, %4 ;increase use of left bswap
+  %6 = mul i32 %2, %5 ;increase use of right bswap
+
+  ret i32 %6
+}
+
+; negative test
+define i32 @bs_and_rhs_bs32_multiuse1(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: bs_and_rhs_bs32_multiuse1:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    rev r1, r1
+; CHECK-NEXT:    ands r0, r1
+; CHECK-NEXT:    rev r1, r0
+; CHECK-NEXT:    muls r0, r1, r0
+; CHECK-NEXT:    bx lr
+  %1 = tail call i32 @llvm.bswap.i32(i32 %b)
+  %2 = and i32 %1, %a
+  %3 = tail call i32 @llvm.bswap.i32(i32 %2)
+  %4 = mul i32 %2, %3 ;increase use of logical op
+  ret i32 %4
+}
+
+; negative test
+define i32 @bs_xor_rhs_brev32(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: bs_xor_rhs_brev32:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    rbit r1, r1
+; CHECK-NEXT:    eors r0, r1
+; CHECK-NEXT:    rev r0, r0
+; CHECK-NEXT:    bx lr
+  %1 = tail call i32 @llvm.bitreverse.i32(i32 %b)
+  %2 = xor i32 %a, %1
+  %3 = tail call i32 @llvm.bswap.i32(i32 %2)
+  ret i32 %3
+}
+

llvm/test/CodeGen/X86/combine-bitreverse.ll

@@ -8,6 +8,7 @@
 declare i32 @llvm.bitreverse.i32(i32) readnone
 declare i64 @llvm.bitreverse.i64(i64) readnone
 declare <4 x i32> @llvm.bitreverse.v4i32(<4 x i32>) readnone
+declare i32 @llvm.bswap.i32(i32) readnone
 
 ; fold (bitreverse undef) -> undef
 define i32 @test_undef() nounwind {

llvm/test/CodeGen/X86/combine-bswap.ll

@@ -255,6 +255,168 @@ define i32 @test_bswap32_shift17(i32 %a0) {
   ret i32 %b
 }
 
+define i32 @bs_and_lhs_bs32(i32 %a, i32 %b) #0 {
+; X86-LABEL: bs_and_lhs_bs32:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    bswapl %eax
+; X86-NEXT:    andl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    bswapl %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: bs_and_lhs_bs32:
+; X64:       # %bb.0:
+; X64-NEXT:    movl %edi, %eax
+; X64-NEXT:    bswapl %eax
+; X64-NEXT:    andl %esi, %eax
+; X64-NEXT:    bswapl %eax
+; X64-NEXT:    retq
+  %1 = tail call i32 @llvm.bswap.i32(i32 %a)
+  %2 = and i32 %1, %b
+  %3 = tail call i32 @llvm.bswap.i32(i32 %2)
+  ret i32 %3
+}
+
+define i64 @bs_or_lhs_bs64(i64 %a, i64 %b) #0 {
+; X86-LABEL: bs_or_lhs_bs64:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %edx
+; X86-NEXT:    bswapl %eax
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    orl {{[0-9]+}}(%esp), %edx
+; X86-NEXT:    orl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    bswapl %eax
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    retl
+;
+; X64-LABEL: bs_or_lhs_bs64:
+; X64:       # %bb.0:
+; X64-NEXT:    movq %rdi, %rax
+; X64-NEXT:    bswapq %rax
+; X64-NEXT:    orq %rsi, %rax
+; X64-NEXT:    bswapq %rax
+; X64-NEXT:    retq
+  %1 = tail call i64 @llvm.bswap.i64(i64 %a)
+  %2 = or i64 %1, %b
+  %3 = tail call i64 @llvm.bswap.i64(i64 %2)
+  ret i64 %3
+}
+
+define i64 @bs_xor_rhs_bs64(i64 %a, i64 %b) #0 {
+; X86-LABEL: bs_xor_rhs_bs64:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %edx
+; X86-NEXT:    bswapl %eax
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    xorl {{[0-9]+}}(%esp), %edx
+; X86-NEXT:    xorl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    bswapl %eax
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    retl
+;
+; X64-LABEL: bs_xor_rhs_bs64:
+; X64:       # %bb.0:
+; X64-NEXT:    movq %rsi, %rax
+; X64-NEXT:    bswapq %rax
+; X64-NEXT:    xorq %rdi, %rax
+; X64-NEXT:    bswapq %rax
+; X64-NEXT:    retq
+  %1 = tail call i64 @llvm.bswap.i64(i64 %b)
+  %2 = xor i64 %a, %1
+  %3 = tail call i64 @llvm.bswap.i64(i64 %2)
+  ret i64 %3
+}
+
+define i32 @bs_and_all_operand_multiuse(i32 %a, i32 %b) #0 {
+; X86-LABEL: bs_and_all_operand_multiuse:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    bswapl %ecx
+; X86-NEXT:    bswapl %eax
+; X86-NEXT:    movl %ecx, %edx
+; X86-NEXT:    andl %eax, %edx
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    imull %ecx, %eax
+; X86-NEXT:    imull %edx, %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: bs_and_all_operand_multiuse:
+; X64:       # %bb.0:
+; X64-NEXT:    bswapl %edi
+; X64-NEXT:    bswapl %esi
+; X64-NEXT:    movl %edi, %eax
+; X64-NEXT:    andl %esi, %eax
+; X64-NEXT:    bswapl %eax
+; X64-NEXT:    imull %edi, %esi
+; X64-NEXT:    imull %esi, %eax
+; X64-NEXT:    retq
+  %1 = tail call i32 @llvm.bswap.i32(i32 %a)
+  %2 = tail call i32 @llvm.bswap.i32(i32 %b)
+  %3 = and i32 %1, %2
+  %4 = tail call i32 @llvm.bswap.i32(i32 %3)
+  %5 = mul i32 %1, %4 ;increase use of left bswap
+  %6 = mul i32 %2, %5 ;increase use of right bswap
+
+  ret i32 %6
+}
+
+; negative test
+define i32 @bs_and_rhs_bs32_multiuse1(i32 %a, i32 %b) #0 {
+; X86-LABEL: bs_and_rhs_bs32_multiuse1:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    bswapl %ecx
+; X86-NEXT:    andl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl %ecx, %eax
+; X86-NEXT:    bswapl %eax
+; X86-NEXT:    imull %ecx, %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: bs_and_rhs_bs32_multiuse1:
+; X64:       # %bb.0:
+; X64-NEXT:    bswapl %esi
+; X64-NEXT:    andl %edi, %esi
+; X64-NEXT:    movl %esi, %eax
+; X64-NEXT:    bswapl %eax
+; X64-NEXT:    imull %esi, %eax
+; X64-NEXT:    retq
+  %1 = tail call i32 @llvm.bswap.i32(i32 %b)
+  %2 = and i32 %1, %a
+  %3 = tail call i32 @llvm.bswap.i32(i32 %2)
+  %4 = mul i32 %2, %3 ;increase use of logical op
+  ret i32 %4
+}
+
+; negative test
+define i32 @bs_and_rhs_bs32_multiuse2(i32 %a, i32 %b) #0 {
+; X86-LABEL: bs_and_rhs_bs32_multiuse2:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    bswapl %ecx
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    andl %ecx, %eax
+; X86-NEXT:    bswapl %eax
+; X86-NEXT:    imull %ecx, %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: bs_and_rhs_bs32_multiuse2:
+; X64:       # %bb.0:
+; X64-NEXT:    movl %edi, %eax
+; X64-NEXT:    bswapl %esi
+; X64-NEXT:    andl %esi, %eax
+; X64-NEXT:    bswapl %eax
+; X64-NEXT:    imull %esi, %eax
+; X64-NEXT:    retq
+  %1 = tail call i32 @llvm.bswap.i32(i32 %b)
+  %2 = and i32 %1, %a
+  %3 = tail call i32 @llvm.bswap.i32(i32 %2)
+  %4 = mul i32 %1, %3 ;increase use of inner bswap
+  ret i32 %4
+}
+
 ; negative test
 define i64 @test_bswap64_shift17(i64 %a0) {
 ; X86-LABEL: test_bswap64_shift17: