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[ARM] Constant Materialize: imms with specific value can be encoded into mov.w 

Summary: Thumb2 supports encoding immediates with specific patterns into mov.w by splatting the low 8 bits into other bytes.

I'm resubmitting this patch. The test case in the original commit
r277610 does not specify triple, so builds with differnt default triple
will have different output.

This patch fixed trile as thumb-darwin-apple.

Reviewers: john.brawn, jmolloy, bruno

Subscribers: jmolloy, aemerson, rengolin, samparker, llvm-commits

Differential Revision: https://reviews.llvm.org/D23090

llvm-svn: 277865
This commit is contained in:
Weiming Zhao 2016-08-05 20:58:29 +00:00
parent 500929df9c
commit f68a6a720c
2 changed files with 60 additions and 4 deletions
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4
llvm/lib/Target/ARM/ARMISelDAGToDAG.cpp
View File

@ -476,7 +476,9 @@ bool ARMDAGToDAGISel::isShifterOpProfitable(const SDValue &Shift,
unsigned ARMDAGToDAGISel::ConstantMaterializationCost(unsigned Val) const {
if (Subtarget->isThumb()) {
if (Val <= 255) return 1; // MOV
if (Subtarget->hasV6T2Ops() && Val <= 0xffff) return 1; // MOVW
if (Subtarget->hasV6T2Ops() &&
(Val <= 0xffff || ARM_AM::getT2SOImmValSplatVal(Val) != -1))
return 1; // MOVW
if (Val <= 510) return 2; // MOV + ADDi8
if (~Val <= 255) return 2; // MOV + MVN
if (ARM_AM::isThumbImmShiftedVal(Val)) return 2; // MOV + LSL

60
llvm/test/CodeGen/ARM/subtarget-no-movt.ll
View File

@ -1,24 +1,40 @@
; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - | FileCheck -check-prefix=NO-OPTION %s
; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - -mattr=-no-movt | FileCheck -check-prefix=USE-MOVT %s
; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - -mattr=+no-movt | FileCheck -check-prefix=NO-USE-MOVT %s
; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - -O0 | FileCheck -check-prefix=NO-OPTION %s
; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - -O0 -mattr=-no-movt | FileCheck -check-prefix=USE-MOVT %s
; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - -O0 -mattr=+no-movt | FileCheck -check-prefix=NO-USE-MOVT %s
; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - -O0 | FileCheck -check-prefix=NO-OPTION-O0 %s
; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - -O0 -mattr=-no-movt | FileCheck -check-prefix=USE-MOVT-O0 %s
; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - -O0 -mattr=+no-movt | FileCheck -check-prefix=NO-USE-MOVT-O0 %s
target triple = "thumb-apple-darwin"
; NO-OPTION-LABEL: {{_?}}foo0
; NO-OPTION: ldr [[R0:r[0-9]+]], [[L0:.*]]
; NO-OPTION: [[L0]]:
; NO-OPTION: .long 2296237089
; NO-OPTION-O0-LABEL: {{_?}}foo0
; NO-OPTION-O0: ldr [[R0:r[0-9]+]], [[L0:.*]]
; NO-OPTION-O0: [[L0]]:
; NO-OPTION-O0: .long 2296237089
; USE-MOVT-LABEL: {{_?}}foo0
; USE-MOVT: movw [[R0:r[0-9]+]], #52257
; USE-MOVT: movt [[R0]], #35037
; USE-MOVT-O0-LABEL: {{_?}}foo0
; USE-MOVT-O0: movw [[R0:r[0-9]+]], #52257
; USE-MOVT-O0: movt [[R0]], #35037
; NO-USE-MOVT-LABEL: {{_?}}foo0
; NO-USE-MOVT: ldr [[R0:r[0-9]+]], [[L0:.*]]
; NO-USE-MOVT: [[L0]]:
; NO-USE-MOVT: .long 2296237089
; NO-USE-MOVT-O0-LABEL: {{_?}}foo0
; NO-USE-MOVT-O0: ldr [[R0:r[0-9]+]], [[L0:.*]]
; NO-USE-MOVT-O0: [[L0]]:
; NO-USE-MOVT-O0: .long 2296237089
define i32 @foo0(i32 %a) #0 {
%1 = xor i32 -1998730207, %a
ret i32 %1
@ -28,18 +44,56 @@ define i32 @foo0(i32 %a) #0 {
; NO-OPTION: movw [[R0:r[0-9]+]], #52257
; NO-OPTION: movt [[R0]], #35037
; NO-OPTION-O0-LABEL: {{_?}}foo1
; NO-OPTION-O0: movw [[R0:r[0-9]+]], #52257
; NO-OPTION-O0: movt [[R0]], #35037
; USE-MOVT-LABEL: {{_?}}foo1
; USE-MOVT: movw [[R0:r[0-9]+]], #52257
; USE-MOVT: movt [[R0]], #35037
; USE-MOVT-O0-LABEL: {{_?}}foo1
; USE-MOVT-O0: movw [[R0:r[0-9]+]], #52257
; USE-MOVT-O0: movt [[R0]], #35037
; NO-USE-MOVT-LABEL: {{_?}}foo1
; NO-USE-MOVT: ldr [[R0:r[0-9]+]], [[L0:.*]]
; NO-USE-MOVT: [[L0]]:
; NO-USE-MOVT: .long 2296237089
; NO-USE-MOVT-O0-LABEL: {{_?}}foo1
; NO-USE-MOVT-O0: ldr [[R0:r[0-9]+]], [[L0:.*]]
; NO-USE-MOVT-O0: [[L0]]:
; NO-USE-MOVT-O0: .long 2296237089
define i32 @foo1(i32 %a) {
%1 = xor i32 -1998730207, %a
ret i32 %1
}
; NO-OPTION-LABEL: {{_?}}foo2
; NO-OPTION: mov.w [[R0:r[0-9]+]], #-536813568
; USE-MOVT-LABEL: {{_?}}foo2
; USE-MOVT: mov.w [[R0:r[0-9]+]], #-536813568
; NO-USE-MOVT-LABEL: {{_?}}foo2
; NO-USE-MOVT: mov.w [[R0:r[0-9]+]], #-536813568
; NO-OPTION-O0-LABEL: {{_?}}foo2
; NO-OPTION-O0: movw [[R0:r[0-9]+]], #57344
; NO-OPTION-O0: movt [[R0]], #57344
; USE-MOVT-O0-LABEL: {{_?}}foo2
; USE-MOVT-O0: movw [[R0:r[0-9]+]], #57344
; USE-MOVTT-O0: movt [[R0]], #57344
; NO-USE-MOVT-O0-LABEL: {{_?}}foo2
; NO-USE-MOVT-O0: ldr [[R0:r[0-9]+]], [[L0:.*]]
; NO-USE-MOVT-O0: [[L0]]:
; NO-USE-MOVT-O0: .long 3758153728 @ 0xe000e000
define i32 @foo2() {
%1 = load i32, i32* inttoptr (i32 -536813568 to i32*) ; load from 0xe000e000
ret i32 %1
}
attributes #0 = { "target-features"="+no-movt" }