; RUN: llc < %s -relocation-model=pic -disable-fp-elim -mcpu=cortex-a8 -pre-RA-sched=source | FileCheck %s target triple = "thumbv7-apple-ios" ; <rdar://problem/10032939> ; ; The vector %v2 is built like this: ; ; %vreg6:ssub_1<def> = VMOVSR %vreg0<kill>, pred:14, pred:%noreg, %vreg6<imp-def>; DPR_VFP2:%vreg6 GPR:%vreg0 ; %vreg6:ssub_0<def> = VLDRS <cp#0>, 0, pred:14, pred:%noreg; mem:LD4[ConstantPool] DPR_VFP2:%vreg6 ; ; When %vreg6 spills, the VLDRS constant pool load cannot be rematerialized ; since it implicitly reads the ssub_1 sub-register. ; ; CHECK: f1 ; CHECK: vmov s1, r0 ; CHECK: vldr.32 s0, LCPI ; The vector must be spilled: ; CHECK: vstr.64 d0, ; CHECK: asm clobber d0 ; And reloaded after the asm: ; CHECK: vldr.64 [[D16:d[0-9]+]], ; CHECK: vstr.64 [[D16]], [r1] define void @f1(float %x, <2 x float>* %p) { %v1 = insertelement <2 x float> undef, float %x, i32 1 %v2 = insertelement <2 x float> %v1, float 0x400921FB60000000, i32 0 %y = call double asm sideeffect "asm clobber $0", "=w,0,~{d1},~{d2},~{d3},~{d4},~{d5},~{d6},~{d7},~{d8},~{d9},~{d10},~{d11},~{d12},~{d13},~{d14},~{d15},~{d16},~{d17},~{d18},~{d19},~{d20},~{d21},~{d22},~{d23},~{d24},~{d25},~{d26},~{d27},~{d28},~{d29},~{d30},~{d31}"(<2 x float> %v2) nounwind store <2 x float> %v2, <2 x float>* %p, align 8 ret void } ; On the other hand, when the partial redef doesn't read the full register ; because the bits are undef, we should rematerialize. The vector is now built ; like this: ; ; %vreg2:ssub_0<def> = VLDRS <cp#0>, 0, pred:14, pred:%noreg, %vreg2<imp-def>; mem:LD4[ConstantPool] ; ; The extra <imp-def> operand indicates that the instruction fully defines the ; virtual register. It doesn't read the old value. ; ; CHECK: f2 ; CHECK: vldr.32 s0, LCPI ; The vector must not be spilled: ; CHECK-NOT: vstr.64 ; CHECK: asm clobber d0 ; But instead rematerialize after the asm: ; CHECK: vldr.32 [[S0:s[0-9]+]], LCPI ; CHECK: vstr.64 [[D0:d[0-9]+]], [r0] define void @f2(<2 x float>* %p) { %v2 = insertelement <2 x float> undef, float 0x400921FB60000000, i32 0 %y = call double asm sideeffect "asm clobber $0", "=w,0,~{d1},~{d2},~{d3},~{d4},~{d5},~{d6},~{d7},~{d8},~{d9},~{d10},~{d11},~{d12},~{d13},~{d14},~{d15},~{d16},~{d17},~{d18},~{d19},~{d20},~{d21},~{d22},~{d23},~{d24},~{d25},~{d26},~{d27},~{d28},~{d29},~{d30},~{d31}"(<2 x float> %v2) nounwind store <2 x float> %v2, <2 x float>* %p, align 8 ret void }