llvm-project/llvm/test/CodeGen/X86/bypass-slow-division-tune.ll

; Check that a division is bypassed when appropriate only.
; RUN: llc -mtriple=x86_64-unknown-linux-gnu -mcpu=atom       < %s | FileCheck -check-prefixes=ATOM,CHECK %s
; RUN: llc -mtriple=x86_64-unknown-linux-gnu -mcpu=silvermont < %s | FileCheck -check-prefixes=REST,CHECK %s
; RUN: llc -mtriple=x86_64-unknown-linux-gnu -mcpu=skylake    < %s | FileCheck -check-prefixes=REST,CHECK %s

; Verify that div32 is bypassed only for Atoms.
define i32 @div32(i32 %a, i32 %b) {
entry:
; ATOM-LABEL: div32:
; ATOM: orl   %{{.*}}, [[REG:%[a-z]+]]
; ATOM: testl $-256, [[REG]]
; ATOM: divb
;
; REST-LABEL: div32:
; REST-NOT: divb
;
  %div = sdiv i32 %a, %b
  ret i32 %div
}

; Verify that div64 is always bypassed.
define i64 @div64(i64 %a, i64 %b) {
entry:
; CHECK-LABEL: div64:
; CHECK:     orq     %{{.*}}, [[REG:%[a-z]+]]
; CHECK:     shrq    $32, [[REG]]
; CHECK:     divl
;
  %div = sdiv i64 %a, %b
  ret i64 %div
}


; Verify that no extra code is generated when optimizing for size.

define i64 @div64_optsize(i64 %a, i64 %b) optsize {
; CHECK-LABEL: div64_optsize:
; CHECK-NOT: divl
  %div = sdiv i64 %a, %b
  ret i64 %div
}

define i32 @div32_optsize(i32 %a, i32 %b) optsize {
; CHECK-LABEL: div32_optsize:
; CHECK-NOT: divb
  %div = sdiv i32 %a, %b
  ret i32 %div
}

define i32 @div32_minsize(i32 %a, i32 %b) minsize {
; CHECK-LABEL: div32_minsize:
; CHECK-NOT: divb
  %div = sdiv i32 %a, %b
  ret i32 %div
}