ARM: provide a new generic hint intrinsic

Introduce the llvm.arm.hint(i32) intrinsic that can be used to inject hints into
the instruction stream. This is particularly useful for generating IR from a
compiler where the user may inject an intrinsic (e.g. __yield). These are then
pattern substituted into the correct instruction which already existed.

llvm-svn: 207242
This commit is contained in:
Saleem Abdulrasool 2014-04-25 17:24:24 +00:00
parent 01bbd1b1c3
commit 7e7c2f9ca6
5 changed files with 76 additions and 3 deletions

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@ -123,6 +123,7 @@ def int_arm_crc32cw : Intrinsic<[llvm_i32_ty], [llvm_i32_ty, llvm_i32_ty],
//===----------------------------------------------------------------------===//
// HINT
def int_arm_sevl : Intrinsic<[], []>;
def int_arm_hint : Intrinsic<[], [llvm_i32_ty]>;
//===----------------------------------------------------------------------===//
// Advanced SIMD (NEON)

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@ -1827,7 +1827,8 @@ PseudoInst<(outs), (ins i32imm:$amt, pred:$p), NoItinerary,
}
def HINT : AI<(outs), (ins imm0_239:$imm), MiscFrm, NoItinerary,
"hint", "\t$imm", []>, Requires<[IsARM, HasV6]> {
"hint", "\t$imm", [(int_arm_hint imm0_239:$imm)]>,
Requires<[IsARM, HasV6]> {
bits<8> imm;
let Inst{27-8} = 0b00110010000011110000;
let Inst{7-0} = imm;

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@ -269,7 +269,8 @@ class T1SystemEncoding<bits<8> opc>
let Inst{7-0} = opc;
}
def tHINT : T1pI<(outs), (ins imm0_15:$imm), NoItinerary, "hint", "\t$imm", []>,
def tHINT : T1pI<(outs), (ins imm0_15:$imm), NoItinerary, "hint", "\t$imm",
[(int_arm_hint imm0_15:$imm)]>,
T1SystemEncoding<0x00>,
Requires<[IsThumb, HasV6M]> {
bits<4> imm;

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@ -3671,7 +3671,8 @@ def : t2InstAlias<"cps.w $mode", (t2CPS1p imm0_31:$mode), 0>;
// A6.3.4 Branches and miscellaneous control
// Table A6-14 Change Processor State, and hint instructions
def t2HINT : T2I<(outs), (ins imm0_239:$imm), NoItinerary, "hint", ".w\t$imm",[]> {
def t2HINT : T2I<(outs), (ins imm0_239:$imm), NoItinerary, "hint", ".w\t$imm",
[(int_arm_hint imm0_239:$imm)]> {
bits<8> imm;
let Inst{31-3} = 0b11110011101011111000000000000;
let Inst{7-0} = imm;

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@ -0,0 +1,69 @@
; RUN: llc -mtriple armv7-eabi -o - %s | FileCheck %s
; RUN: llc -mtriple thumbv6m-eabi -o - %s | FileCheck %s
; RUN: llc -mtriple thumbv7-eabi -o - %s | FileCheck %s
declare void @llvm.arm.hint(i32) nounwind
define void @hint_nop() {
entry:
tail call void @llvm.arm.hint(i32 0) nounwind
ret void
}
; CHECK-LABEL: hint_nop
; CHECK: nop
define void @hint_yield() {
entry:
tail call void @llvm.arm.hint(i32 1) nounwind
ret void
}
; CHECK-LABEL: hint_yield
; CHECK: yield
define void @hint_wfe() {
entry:
tail call void @llvm.arm.hint(i32 2) nounwind
ret void
}
; CHECK-LABEL: hint_wfe
; CHECK: wfe
define void @hint_wfi() {
entry:
tail call void @llvm.arm.hint(i32 3) nounwind
ret void
}
; CHECK-LABEL: hint_wfi
; CHECK: wfi
define void @hint_sev() {
entry:
tail call void @llvm.arm.hint(i32 4) nounwind
ret void
}
; CHECK-LABEL: hint_sev
; CHECK: sev
define void @hint_sevl() {
entry:
tail call void @llvm.arm.hint(i32 5) nounwind
ret void
}
; CHECK-LABEL: hint_sevl
; CHECK: hint #5
define void @hint_undefined() {
entry:
tail call void @llvm.arm.hint(i32 8) nounwind
ret void
}
; CHECK-LABEL: hint_undefined
; CHECK: hint #8