ARM: Remove a (false) dependency on the memoryoperand's value as we do not use

it at the moment.
This allows to form more paired loads even when stack coloring pass destroys the
memoryoperand's value.

<rdar://problem/13978317>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184492 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Quentin Colombet 2013-06-20 22:51:44 +00:00
parent 846565924a
commit 2b7cdf09a1
3 changed files with 46 additions and 3 deletions

View File

@ -1602,8 +1602,9 @@ ARMPreAllocLoadStoreOpt::CanFormLdStDWord(MachineInstr *Op0, MachineInstr *Op1,
return false;
// Make sure the base address satisfies i64 ld / st alignment requirement.
// At the moment, we ignore the memoryoperand's value.
// If we want to use AliasAnalysis, we should check it accordingly.
if (!Op0->hasOneMemOperand() ||
!(*Op0->memoperands_begin())->getValue() ||
(*Op0->memoperands_begin())->isVolatile())
return false;

View File

@ -24,7 +24,14 @@ entry:
}
; CHECK: main:
; CHECK: ldm r0, {r2, r3}
; CHECK: movw [[BASE:r[0-9]+]], :lower16:static_val
; CHECK: movt [[BASE]], :upper16:static_val
; ldm is not formed when the coalescer failed to coalesce everything.
; CHECK: ldr r2, {{\[}}[[BASE]]{{\]}}
; CHECK: ldr [[TMP:r[0-9]+]], {{\[}}[[BASE]], #4{{\]}}
; CHECK: movw r0, #555
; Currently the coalescer misses this opportunity.
; CHECK: mov r3, [[TMP]]
define i32 @main() {
entry:
call void (i32, ...)* @test_byval_8_bytes_alignment(i32 555, %struct_t* byval @static_val)
@ -47,7 +54,14 @@ entry:
}
; CHECK: main_fixed_arg:
; CHECK: ldm r0, {r2, r3}
; CHECK: movw [[BASE:r[0-9]+]], :lower16:static_val
; CHECK: movt [[BASE]], :upper16:static_val
; ldm is not formed when the coalescer failed to coalesce everything.
; CHECK: ldr r2, {{\[}}[[BASE]]{{\]}}
; CHECK: ldr [[TMP:r[0-9]+]], {{\[}}[[BASE]], #4{{\]}}
; CHECK: movw r0, #555
; Currently the coalescer misses this opportunity.
; CHECK: mov r3, [[TMP]]
define i32 @main_fixed_arg() {
entry:
call void (i32, %struct_t*)* @test_byval_8_bytes_alignment_fixed_arg(i32 555, %struct_t* byval @static_val)

View File

@ -67,3 +67,31 @@ bb: ; preds = %bb, %entry
return: ; preds = %bb, %entry
ret void
}
; rdar://13978317
; Pair of loads not formed when lifetime markers are set.
%struct.Test = type { i32, i32, i32 }
@TestVar = external global %struct.Test
define void @Func1() nounwind ssp {
; CHECK: @Func1
entry:
; A8: movw [[BASE:r[0-9]+]], :lower16:{{.*}}TestVar{{.*}}
; A8: movt [[BASE]], :upper16:{{.*}}TestVar{{.*}}
; A8: ldrd [[FIELD1:r[0-9]+]], [[FIELD2:r[0-9]+]], {{\[}}[[BASE]], #4]
; A8-NEXT: add [[FIELD1]], [[FIELD2]]
; A8-NEXT: str [[FIELD1]], {{\[}}[[BASE]]{{\]}}
%orig_blocks = alloca [256 x i16], align 2
%0 = bitcast [256 x i16]* %orig_blocks to i8*call void @llvm.lifetime.start(i64 512, i8* %0) nounwind
%tmp1 = load i32* getelementptr inbounds (%struct.Test* @TestVar, i32 0, i32 1), align 4
%tmp2 = load i32* getelementptr inbounds (%struct.Test* @TestVar, i32 0, i32 2), align 4
%add = add nsw i32 %tmp2, %tmp1
store i32 %add, i32* getelementptr inbounds (%struct.Test* @TestVar, i32 0, i32 0), align 4
call void @llvm.lifetime.end(i64 512, i8* %0) nounwind
ret void
}
declare void @llvm.lifetime.start(i64, i8* nocapture) nounwind
declare void @llvm.lifetime.end(i64, i8* nocapture) nounwind