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

56 lines
1.4 KiB
LLVM

; 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
}