llvm-6502/test/CodeGen/ARM/machine-licm.ll
Evan Cheng 53519f015e Last round of fixes for movw + movt global address codegen.
1. Fixed ARM pc adjustment.
2. Fixed dynamic-no-pic codegen
3. CSE of pc-relative load of global addresses.

It's now enabled by default for Darwin.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123991 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-21 18:55:51 +00:00

67 lines
2.5 KiB
LLVM

; RUN: llc < %s -mtriple=thumb-apple-darwin -relocation-model=pic -disable-fp-elim | FileCheck %s -check-prefix=THUMB
; RUN: llc < %s -mtriple=arm-apple-darwin -relocation-model=pic -disable-fp-elim | FileCheck %s -check-prefix=ARM
; RUN: llc < %s -mtriple=arm-apple-darwin -relocation-model=pic -disable-fp-elim -mattr=+v6t2 | FileCheck %s -check-prefix=MOVT
; rdar://7353541
; rdar://7354376
; rdar://8887598
; The generated code is no where near ideal. It's not recognizing the two
; constantpool entries being loaded can be merged into one.
@GV = external global i32 ; <i32*> [#uses=2]
define void @t(i32* nocapture %vals, i32 %c) nounwind {
entry:
; ARM: t:
; ARM: ldr [[REGISTER_1:r[0-9]+]], LCPI0_0
; Unfortunately currently ARM codegen doesn't cse the ldr from constantpool.
; The issue is it can be read by an "add pc" or a "ldr [pc]" so it's messy
; to add the pseudo instructions to make sure they are CSE'ed at the same
; time as the "ldr cp".
; ARM: ldr r{{[0-9]+}}, LCPI0_1
; ARM: LPC0_0:
; ARM: ldr r{{[0-9]+}}, [pc, [[REGISTER_1]]]
; ARM: ldr r{{[0-9]+}}, [r{{[0-9]+}}]
; MOVT: t:
; MOVT: movw [[REGISTER_2:r[0-9]+]], :lower16:(L_GV$non_lazy_ptr-(LPC0_0+8))
; MOVT: movt [[REGISTER_2]], :upper16:(L_GV$non_lazy_ptr-(LPC0_0+8))
; MOVT: LPC0_0:
; MOVT: ldr r{{[0-9]+}}, [pc, [[REGISTER_2]]]
; MOVT: ldr r{{[0-9]+}}, [r{{[0-9]+}}]
; THUMB: t:
%0 = icmp eq i32 %c, 0 ; <i1> [#uses=1]
br i1 %0, label %return, label %bb.nph
bb.nph: ; preds = %entry
; ARM: LCPI0_0:
; ARM: LCPI0_1:
; ARM: .section
; THUMB: BB#1
; THUMB: ldr.n r2, LCPI0_0
; THUMB: add r2, pc
; THUMB: ldr r{{[0-9]+}}, [r2]
; THUMB: LBB0_2
; THUMB: LCPI0_0:
; THUMB-NOT: LCPI0_1:
; THUMB: .section
%.pre = load i32* @GV, align 4 ; <i32> [#uses=1]
br label %bb
bb: ; preds = %bb, %bb.nph
%1 = phi i32 [ %.pre, %bb.nph ], [ %3, %bb ] ; <i32> [#uses=1]
%i.03 = phi i32 [ 0, %bb.nph ], [ %4, %bb ] ; <i32> [#uses=2]
%scevgep = getelementptr i32* %vals, i32 %i.03 ; <i32*> [#uses=1]
%2 = load i32* %scevgep, align 4 ; <i32> [#uses=1]
%3 = add nsw i32 %1, %2 ; <i32> [#uses=2]
store i32 %3, i32* @GV, align 4
%4 = add i32 %i.03, 1 ; <i32> [#uses=2]
%exitcond = icmp eq i32 %4, %c ; <i1> [#uses=1]
br i1 %exitcond, label %return, label %bb
return: ; preds = %bb, %entry
ret void
}