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

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; bswap should be constant folded when it is passed a constant argument

; RUN: llc < %s -mtriple=i686-- -mcpu=i686 | FileCheck %s
; RUN: llc < %s -mtriple=x86_64-- | FileCheck %s --check-prefix=CHECK64

declare i16 @llvm.bswap.i16(i16)
declare i32 @llvm.bswap.i32(i32)
declare i64 @llvm.bswap.i64(i64)

define i16 @W(i16 %A) {
; CHECK-LABEL: W:
; CHECK:       # %bb.0:
; CHECK-NEXT:    movzwl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT:    rolw $8, %ax
; CHECK-NEXT:    retl
;
; CHECK64-LABEL: W:
; CHECK64:       # %bb.0:
; CHECK64-NEXT:    movl %edi, %eax
; CHECK64-NEXT:    rolw $8, %ax
; CHECK64-NEXT:    # kill: def $ax killed $ax killed $eax
; CHECK64-NEXT:    retq
        %Z = call i16 @llvm.bswap.i16( i16 %A )         ; <i16> [#uses=1]
        ret i16 %Z
}

define i32 @X(i32 %A) {
; CHECK-LABEL: X:
; CHECK:       # %bb.0:
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT:    bswapl %eax
; CHECK-NEXT:    retl
;
; CHECK64-LABEL: X:
; CHECK64:       # %bb.0:
; CHECK64-NEXT:    movl %edi, %eax
; CHECK64-NEXT:    bswapl %eax
; CHECK64-NEXT:    retq
        %Z = call i32 @llvm.bswap.i32( i32 %A )         ; <i32> [#uses=1]
        ret i32 %Z
}

define i64 @Y(i64 %A) {
; CHECK-LABEL: Y:
; CHECK:       # %bb.0:
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %edx
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT:    bswapl %eax
; CHECK-NEXT:    bswapl %edx
; CHECK-NEXT:    retl
;
; CHECK64-LABEL: Y:
; CHECK64:       # %bb.0:
; CHECK64-NEXT:    movq %rdi, %rax
; CHECK64-NEXT:    bswapq %rax
; CHECK64-NEXT:    retq
        %Z = call i64 @llvm.bswap.i64( i64 %A )         ; <i64> [#uses=1]
        ret i64 %Z
}

; This isn't really a bswap test, but the potential probem is
; easier to see with bswap vs. other ops. The transform in
; question starts with a bitwise logic op and tries to hoist
; those ahead of other ops. But that's not generally profitable
; when the other ops have other uses (and it might not be safe
; either due to unconstrained instruction count growth).

define i32 @bswap_multiuse(i32 %x, i32 %y, i32* %p1, i32* %p2) nounwind {
; CHECK-LABEL: bswap_multiuse:
; CHECK:       # %bb.0:
; CHECK-NEXT:    pushl %esi
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %edx
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %esi
; CHECK-NEXT:    bswapl %esi
; CHECK-NEXT:    bswapl %eax
; CHECK-NEXT:    movl %esi, (%edx)
; CHECK-NEXT:    movl %eax, (%ecx)
; CHECK-NEXT:    orl %esi, %eax
; CHECK-NEXT:    popl %esi
; CHECK-NEXT:    retl
;
; CHECK64-LABEL: bswap_multiuse:
; CHECK64:       # %bb.0:
; CHECK64-NEXT:    movl %esi, %eax
; CHECK64-NEXT:    bswapl %edi
; CHECK64-NEXT:    bswapl %eax
; CHECK64-NEXT:    movl %edi, (%rdx)
; CHECK64-NEXT:    movl %eax, (%rcx)
; CHECK64-NEXT:    orl %edi, %eax
; CHECK64-NEXT:    retq
  %xt = call i32 @llvm.bswap.i32(i32 %x)
  %yt = call i32 @llvm.bswap.i32(i32 %y)
  store i32 %xt, i32* %p1
  store i32 %yt, i32* %p2
  %r = or i32 %xt, %yt
  ret i32 %r
}

; rdar://9164521
define i32 @test1(i32 %a) nounwind readnone {
; CHECK-LABEL: test1:
; CHECK:       # %bb.0:
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT:    bswapl %eax
; CHECK-NEXT:    shrl $16, %eax
; CHECK-NEXT:    retl
;
; CHECK64-LABEL: test1:
; CHECK64:       # %bb.0:
; CHECK64-NEXT:    movl %edi, %eax
; CHECK64-NEXT:    bswapl %eax
; CHECK64-NEXT:    shrl $16, %eax
; CHECK64-NEXT:    retq
  %and = lshr i32 %a, 8
  %shr3 = and i32 %and, 255
  %and2 = shl i32 %a, 8
  %shl = and i32 %and2, 65280
  %or = or i32 %shr3, %shl
  ret i32 %or
}

define i32 @test2(i32 %a) nounwind readnone {
; CHECK-LABEL: test2:
; CHECK:       # %bb.0:
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT:    bswapl %eax
; CHECK-NEXT:    sarl $16, %eax
; CHECK-NEXT:    retl
;
; CHECK64-LABEL: test2:
; CHECK64:       # %bb.0:
; CHECK64-NEXT:    movl %edi, %eax
; CHECK64-NEXT:    bswapl %eax
; CHECK64-NEXT:    sarl $16, %eax
; CHECK64-NEXT:    retq
  %and = lshr i32 %a, 8
  %shr4 = and i32 %and, 255
  %and2 = shl i32 %a, 8
  %or = or i32 %shr4, %and2
  %sext = shl i32 %or, 16
  %conv3 = ashr exact i32 %sext, 16
  ret i32 %conv3
}

@var8 = global i8 0
@var16 = global i16 0

; The "shl" below can move bits into the high parts of the value, so the
; operation is not a "bswap, shr" pair.

; rdar://problem/14814049
define i64 @not_bswap() {
; CHECK-LABEL: not_bswap:
; CHECK:       # %bb.0:
; CHECK-NEXT:    movzwl var16, %eax
; CHECK-NEXT:    movl %eax, %ecx
; CHECK-NEXT:    shrl $8, %ecx
; CHECK-NEXT:    shll $8, %eax
; CHECK-NEXT:    orl %ecx, %eax
; CHECK-NEXT:    xorl %edx, %edx
; CHECK-NEXT:    retl
;
; CHECK64-LABEL: not_bswap:
; CHECK64:       # %bb.0:
; CHECK64-NEXT:    movzwl {{.*}}(%rip), %eax
; CHECK64-NEXT:    movq %rax, %rcx
; CHECK64-NEXT:    shrq $8, %rcx
; CHECK64-NEXT:    shlq $8, %rax
; CHECK64-NEXT:    orq %rcx, %rax
; CHECK64-NEXT:    retq
  %init = load i16, i16* @var16
  %big = zext i16 %init to i64

  %hishifted = lshr i64 %big, 8
  %loshifted = shl i64 %big, 8

  %notswapped = or i64 %hishifted, %loshifted

  ret i64 %notswapped
}

; This time, the lshr (and subsequent or) is completely useless. While it's
; technically correct to convert this into a "bswap, shr", it's suboptimal. A
; simple shl works better.

define i64 @not_useful_bswap() {
; CHECK-LABEL: not_useful_bswap:
; CHECK:       # %bb.0:
; CHECK-NEXT:    movzbl var8, %eax
; CHECK-NEXT:    shll $8, %eax
; CHECK-NEXT:    xorl %edx, %edx
; CHECK-NEXT:    retl
;
; CHECK64-LABEL: not_useful_bswap:
; CHECK64:       # %bb.0:
; CHECK64-NEXT:    movzbl {{.*}}(%rip), %eax
; CHECK64-NEXT:    shlq $8, %rax
; CHECK64-NEXT:    retq
  %init = load i8, i8* @var8
  %big = zext i8 %init to i64

  %hishifted = lshr i64 %big, 8
  %loshifted = shl i64 %big, 8

  %notswapped = or i64 %hishifted, %loshifted

  ret i64 %notswapped
}

; Finally, it *is* OK to just mask off the shl if we know that the value is zero
; beyond 16 bits anyway. This is a legitimate bswap.

define i64 @finally_useful_bswap() {
; CHECK-LABEL: finally_useful_bswap:
; CHECK:       # %bb.0:
; CHECK-NEXT:    movzwl var16, %eax
; CHECK-NEXT:    bswapl %eax
; CHECK-NEXT:    shrl $16, %eax
; CHECK-NEXT:    xorl %edx, %edx
; CHECK-NEXT:    retl
;
; CHECK64-LABEL: finally_useful_bswap:
; CHECK64:       # %bb.0:
; CHECK64-NEXT:    movzwl {{.*}}(%rip), %eax
; CHECK64-NEXT:    bswapq %rax
; CHECK64-NEXT:    shrq $48, %rax
; CHECK64-NEXT:    retq
  %init = load i16, i16* @var16
  %big = zext i16 %init to i64

  %hishifted = lshr i64 %big, 8
  %lomasked = and i64 %big, 255
  %loshifted = shl i64 %lomasked, 8

  %swapped = or i64 %hishifted, %loshifted

  ret i64 %swapped
}

; Make sure we don't assert during type legalization promoting a large
; bswap due to the need for a large shift that won't fit in the i8 returned
; from getShiftAmountTy.
define i528 @large_promotion(i528 %A) nounwind {
; CHECK-LABEL: large_promotion:
; CHECK:       # %bb.0:
; CHECK-NEXT:    pushl %ebp
; CHECK-NEXT:    pushl %ebx
; CHECK-NEXT:    pushl %edi
; CHECK-NEXT:    pushl %esi
; CHECK-NEXT:    subl $44, %esp
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %ebp
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %ebx
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %edi
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %esi
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %edx
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT:    bswapl %eax
; CHECK-NEXT:    bswapl %ecx
; CHECK-NEXT:    shrdl $16, %ecx, %eax
; CHECK-NEXT:    movl %eax, {{[-0-9]+}}(%e{{[sb]}}p) # 4-byte Spill
; CHECK-NEXT:    bswapl %edx
; CHECK-NEXT:    shrdl $16, %edx, %ecx
; CHECK-NEXT:    movl %ecx, {{[-0-9]+}}(%e{{[sb]}}p) # 4-byte Spill
; CHECK-NEXT:    bswapl %esi
; CHECK-NEXT:    shrdl $16, %esi, %edx
; CHECK-NEXT:    movl %edx, {{[-0-9]+}}(%e{{[sb]}}p) # 4-byte Spill
; CHECK-NEXT:    bswapl %edi
; CHECK-NEXT:    shrdl $16, %edi, %esi
; CHECK-NEXT:    movl %esi, {{[-0-9]+}}(%e{{[sb]}}p) # 4-byte Spill
; CHECK-NEXT:    bswapl %ebx
; CHECK-NEXT:    shrdl $16, %ebx, %edi
; CHECK-NEXT:    movl %edi, {{[-0-9]+}}(%e{{[sb]}}p) # 4-byte Spill
; CHECK-NEXT:    bswapl %ebp
; CHECK-NEXT:    shrdl $16, %ebp, %ebx
; CHECK-NEXT:    movl %ebx, {{[-0-9]+}}(%e{{[sb]}}p) # 4-byte Spill
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; CHECK-NEXT:    bswapl %ecx
; CHECK-NEXT:    shrdl $16, %ecx, %ebp
; CHECK-NEXT:    movl %ebp, {{[-0-9]+}}(%e{{[sb]}}p) # 4-byte Spill
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT:    bswapl %eax
; CHECK-NEXT:    shrdl $16, %eax, %ecx
; CHECK-NEXT:    movl %ecx, {{[-0-9]+}}(%e{{[sb]}}p) # 4-byte Spill
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; CHECK-NEXT:    bswapl %ecx
; CHECK-NEXT:    shrdl $16, %ecx, %eax
; CHECK-NEXT:    movl %eax, {{[-0-9]+}}(%e{{[sb]}}p) # 4-byte Spill
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT:    bswapl %eax
; CHECK-NEXT:    shrdl $16, %eax, %ecx
; CHECK-NEXT:    movl %ecx, {{[-0-9]+}}(%e{{[sb]}}p) # 4-byte Spill
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %ebp
; CHECK-NEXT:    bswapl %ebp
; CHECK-NEXT:    shrdl $16, %ebp, %eax
; CHECK-NEXT:    movl %eax, (%esp) # 4-byte Spill
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %ebx
; CHECK-NEXT:    bswapl %ebx
; CHECK-NEXT:    shrdl $16, %ebx, %ebp
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %esi
; CHECK-NEXT:    bswapl %esi
; CHECK-NEXT:    shrdl $16, %esi, %ebx
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %edx
; CHECK-NEXT:    bswapl %edx
; CHECK-NEXT:    shrdl $16, %edx, %esi
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; CHECK-NEXT:    bswapl %ecx
; CHECK-NEXT:    shrdl $16, %ecx, %edx
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %edi
; CHECK-NEXT:    bswapl %edi
; CHECK-NEXT:    shrdl $16, %edi, %ecx
; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT:    movl %ecx, 60(%eax)
; CHECK-NEXT:    movl %edx, 56(%eax)
; CHECK-NEXT:    movl %esi, 52(%eax)
; CHECK-NEXT:    movl %ebx, 48(%eax)
; CHECK-NEXT:    movl %ebp, 44(%eax)
; CHECK-NEXT:    movl (%esp), %ecx # 4-byte Reload
; CHECK-NEXT:    movl %ecx, 40(%eax)
; CHECK-NEXT:    movl {{[-0-9]+}}(%e{{[sb]}}p), %ecx # 4-byte Reload
; CHECK-NEXT:    movl %ecx, 36(%eax)
; CHECK-NEXT:    movl {{[-0-9]+}}(%e{{[sb]}}p), %ecx # 4-byte Reload
; CHECK-NEXT:    movl %ecx, 32(%eax)
; CHECK-NEXT:    movl {{[-0-9]+}}(%e{{[sb]}}p), %ecx # 4-byte Reload
; CHECK-NEXT:    movl %ecx, 28(%eax)
; CHECK-NEXT:    movl {{[-0-9]+}}(%e{{[sb]}}p), %ecx # 4-byte Reload
; CHECK-NEXT:    movl %ecx, 24(%eax)
; CHECK-NEXT:    movl {{[-0-9]+}}(%e{{[sb]}}p), %ecx # 4-byte Reload
; CHECK-NEXT:    movl %ecx, 20(%eax)
; CHECK-NEXT:    movl {{[-0-9]+}}(%e{{[sb]}}p), %ecx # 4-byte Reload
; CHECK-NEXT:    movl %ecx, 16(%eax)
; CHECK-NEXT:    movl {{[-0-9]+}}(%e{{[sb]}}p), %ecx # 4-byte Reload
; CHECK-NEXT:    movl %ecx, 12(%eax)
; CHECK-NEXT:    movl {{[-0-9]+}}(%e{{[sb]}}p), %ecx # 4-byte Reload
; CHECK-NEXT:    movl %ecx, 8(%eax)
; CHECK-NEXT:    movl {{[-0-9]+}}(%e{{[sb]}}p), %ecx # 4-byte Reload
; CHECK-NEXT:    movl %ecx, 4(%eax)
; CHECK-NEXT:    movl {{[-0-9]+}}(%e{{[sb]}}p), %ecx # 4-byte Reload
; CHECK-NEXT:    movl %ecx, (%eax)
; CHECK-NEXT:    shrl $16, %edi
; CHECK-NEXT:    movw %di, 64(%eax)
; CHECK-NEXT:    addl $44, %esp
; CHECK-NEXT:    popl %esi
; CHECK-NEXT:    popl %edi
; CHECK-NEXT:    popl %ebx
; CHECK-NEXT:    popl %ebp
; CHECK-NEXT:    retl $4
;
; CHECK64-LABEL: large_promotion:
; CHECK64:       # %bb.0:
; CHECK64-NEXT:    pushq %rbx
; CHECK64-NEXT:    movq %rdi, %rax
; CHECK64-NEXT:    movq {{[0-9]+}}(%rsp), %rbx
; CHECK64-NEXT:    movq {{[0-9]+}}(%rsp), %r11
; CHECK64-NEXT:    movq {{[0-9]+}}(%rsp), %rdi
; CHECK64-NEXT:    movq {{[0-9]+}}(%rsp), %r10
; CHECK64-NEXT:    bswapq %r10
; CHECK64-NEXT:    bswapq %rdi
; CHECK64-NEXT:    shrdq $48, %rdi, %r10
; CHECK64-NEXT:    bswapq %r11
; CHECK64-NEXT:    shrdq $48, %r11, %rdi
; CHECK64-NEXT:    bswapq %rbx
; CHECK64-NEXT:    shrdq $48, %rbx, %r11
; CHECK64-NEXT:    bswapq %r9
; CHECK64-NEXT:    shrdq $48, %r9, %rbx
; CHECK64-NEXT:    bswapq %r8
; CHECK64-NEXT:    shrdq $48, %r8, %r9
; CHECK64-NEXT:    bswapq %rcx
; CHECK64-NEXT:    shrdq $48, %rcx, %r8
; CHECK64-NEXT:    bswapq %rdx
; CHECK64-NEXT:    shrdq $48, %rdx, %rcx
; CHECK64-NEXT:    bswapq %rsi
; CHECK64-NEXT:    shrdq $48, %rsi, %rdx
; CHECK64-NEXT:    shrq $48, %rsi
; CHECK64-NEXT:    movq %rdx, 56(%rax)
; CHECK64-NEXT:    movq %rcx, 48(%rax)
; CHECK64-NEXT:    movq %r8, 40(%rax)
; CHECK64-NEXT:    movq %r9, 32(%rax)
; CHECK64-NEXT:    movq %rbx, 24(%rax)
; CHECK64-NEXT:    movq %r11, 16(%rax)
; CHECK64-NEXT:    movq %rdi, 8(%rax)
; CHECK64-NEXT:    movq %r10, (%rax)
; CHECK64-NEXT:    movw %si, 64(%rax)
; CHECK64-NEXT:    popq %rbx
; CHECK64-NEXT:    retq
  %Z = call i528 @llvm.bswap.i528(i528 %A)
  ret i528 %Z
}
declare i528 @llvm.bswap.i528(i528)