1 ; RUN: llc < %s -relocation-model=pic -disable-fp-elim -mcpu=cortex-a8 -pre-RA-sched=source | FileCheck %s 2 target triple = "thumbv7-apple-ios" 3 ; <rdar://problem/10032939> 4 ; 5 ; The vector %v2 is built like this: 6 ; 7 ; %vreg6:ssub_1<def> = ... 8 ; %vreg6:ssub_0<def> = VLDRS <cp#0>, 0, pred:14, pred:%noreg; mem:LD4[ConstantPool] DPR_VFP2:%vreg6 9 ; 10 ; When %vreg6 spills, the VLDRS constant pool load cannot be rematerialized 11 ; since it implicitly reads the ssub_1 sub-register. 12 ; 13 ; CHECK: f1 14 ; CHECK: vmov d0, r0, r0 15 ; CHECK: vldr s1, LCPI 16 ; The vector must be spilled: 17 ; CHECK: vstr d0, 18 ; CHECK: asm clobber d0 19 ; And reloaded after the asm: 20 ; CHECK: vldr [[D16:d[0-9]+]], 21 ; CHECK: vstr [[D16]], [r1] 22 define void @f1(float %x, <2 x float>* %p) { 23 %v1 = insertelement <2 x float> undef, float %x, i32 0 24 %v2 = insertelement <2 x float> %v1, float 0x400921FB60000000, i32 1 25 %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 26 store <2 x float> %v2, <2 x float>* %p, align 8 27 ret void 28 } 29 30 ; On the other hand, when the partial redef doesn't read the full register 31 ; because the bits are undef, we should rematerialize. The vector is now built 32 ; like this: 33 ; 34 ; %vreg2:ssub_0<def> = VLDRS <cp#0>, 0, pred:14, pred:%noreg, %vreg2<imp-def>; mem:LD4[ConstantPool] 35 ; 36 ; The extra <imp-def> operand indicates that the instruction fully defines the 37 ; virtual register. It doesn't read the old value. 38 ; 39 ; CHECK: f2 40 ; CHECK: vldr s0, LCPI 41 ; The vector must not be spilled: 42 ; CHECK-NOT: vstr 43 ; CHECK: asm clobber d0 44 ; But instead rematerialize after the asm: 45 ; CHECK: vldr [[S0:s[0-9]+]], LCPI 46 ; CHECK: vstr [[D0:d[0-9]+]], [r0] 47 define void @f2(<2 x float>* %p) { 48 %v2 = insertelement <2 x float> undef, float 0x400921FB60000000, i32 0 49 %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 50 store <2 x float> %v2, <2 x float>* %p, align 8 51 ret void 52 } 53
