Temporarily Revert "RegAllocFast: Rewrite and improve"

as it's breaking a few tests in the lldb test suite.

Bot: http://lab.llvm.org:8011/builders/lldb-arm-ubuntu/builds/4226/steps/test/logs/stdio

This reverts commit c8757ff.

llvm/test/CodeGen/AArch64/GlobalISel/darwin-tls-call-clobber.ll

@@ -31,8 +31,9 @@ target triple = "arm64-apple-ios13.0.0"
 ; This test checks that we don't re-use the register for the variable descriptor
 ; for the second ldr.
 ; CHECK:        adrp	x[[PTR1:[0-9]+]], _t_val@TLVPPAGE
-; CHECK:	ldr	x0, [x[[PTR1]], _t_val@TLVPPAGEOFF]
-; CHECK:	ldr	x[[FPTR:[0-9]+]], [x0]
+; CHECK:	ldr	x[[PTR1]], [x[[PTR1]], _t_val@TLVPPAGEOFF]
+; CHECK:	ldr	x[[FPTR:[0-9]+]], [x[[PTR1]]]
+; CHECK:        mov	x0, x[[PTR1]]
 ; CHECK:        blr     x[[FPTR]]
 
 define void @_Z4funcPKc(i8* %id) {

llvm/test/CodeGen/AArch64/arm64-fast-isel-br.ll

@@ -94,7 +94,7 @@ entry:
   store i32 %c, i32* %c.addr, align 4
   store i64 %d, i64* %d.addr, align 8
   %0 = load i16, i16* %b.addr, align 2
-; CHECK: tbz {{w[0-9]+}}, #0, LBB4_2
+; CHECK: tbz w8, #0, LBB4_2
   %conv = trunc i16 %0 to i1
   br i1 %conv, label %if.then, label %if.end
 

llvm/test/CodeGen/AArch64/arm64-fast-isel-call.ll

@@ -79,7 +79,8 @@ declare i32 @bar(i8 zeroext, i8 zeroext, i8 zeroext, i8 zeroext, i8 zeroext, i8
 define i32 @t2() {
 entry:
 ; CHECK-LABEL: t2
-; CHECK:       mov x0, xzr
+; CHECK:       mov [[REG1:x[0-9]+]], xzr
+; CHECK:       mov x0, [[REG1]]
 ; CHECK:       mov w1, #-8
 ; CHECK:       mov [[REG2:w[0-9]+]], #1023
 ; CHECK:       uxth w2, [[REG2]]

llvm/test/CodeGen/AArch64/arm64-fast-isel-conversion-fallback.ll

@@ -4,8 +4,9 @@
 define i32 @fptosi_wh(half %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: fptosi_wh
-; CHECK: fcvt [[REG:s[0-9]+]], h0
-; CHECK: fcvtzs w0, [[REG]]
+; CHECK: fcvt s0, h0
+; CHECK: fcvtzs [[REG:w[0-9]+]], s0
+; CHECK: mov w0, [[REG]]
   %conv = fptosi half %a to i32
   ret i32 %conv
 }
@@ -14,8 +15,9 @@ entry:
 define i32 @fptoui_swh(half %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: fptoui_swh
-; CHECK: fcvt [[REG:s[0-9]+]], h0
-; CHECK: fcvtzu w0, [[REG]]
+; CHECK: fcvt s0, h0
+; CHECK: fcvtzu [[REG:w[0-9]+]], s0
+; CHECK: mov w0, [[REG]]
   %conv = fptoui half %a to i32
   ret i32 %conv
 }
@@ -24,8 +26,8 @@ entry:
 define half @sitofp_hw_i1(i1 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: sitofp_hw_i1
-; CHECK: sbfx [[REG:w[0-9]+]], w0, #0, #1
-; CHECK: scvtf s0, [[REG]]
+; CHECK: sbfx w8, w0, #0, #1
+; CHECK: scvtf s0, w8
 ; CHECK: fcvt  h0, s0
   %conv = sitofp i1 %a to half
   ret half %conv
@@ -35,8 +37,8 @@ entry:
 define half @sitofp_hw_i8(i8 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: sitofp_hw_i8
-; CHECK: sxtb [[REG:w[0-9]+]], w0
-; CHECK: scvtf s0, [[REG]]
+; CHECK: sxtb w8, w0
+; CHECK: scvtf s0, w8
 ; CHECK: fcvt  h0, s0
   %conv = sitofp i8 %a to half
   ret half %conv
@@ -46,8 +48,8 @@ entry:
 define half @sitofp_hw_i16(i16 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: sitofp_hw_i16
-; CHECK: sxth [[REG:w[0-9]+]], w0
-; CHECK: scvtf s0, [[REG]]
+; CHECK: sxth w8, w0
+; CHECK: scvtf s0, w8
 ; CHECK: fcvt  h0, s0
   %conv = sitofp i16 %a to half
   ret half %conv
@@ -77,8 +79,8 @@ entry:
 define half @uitofp_hw_i1(i1 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: uitofp_hw_i1
-; CHECK: and [[REG:w[0-9]+]], w0, #0x1
-; CHECK: ucvtf s0, [[REG]]
+; CHECK: and w8, w0, #0x1
+; CHECK: ucvtf s0, w8
 ; CHECK: fcvt  h0, s0
   %conv = uitofp i1 %a to half
   ret half %conv
@@ -88,8 +90,8 @@ entry:
 define half @uitofp_hw_i8(i8 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: uitofp_hw_i8
-; CHECK: and [[REG:w[0-9]+]], w0, #0xff
-; CHECK: ucvtf s0, [[REG]]
+; CHECK: and w8, w0, #0xff
+; CHECK: ucvtf s0, w8
 ; CHECK: fcvt  h0, s0
   %conv = uitofp i8 %a to half
   ret half %conv
@@ -99,8 +101,8 @@ entry:
 define half @uitofp_hw_i16(i16 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: uitofp_hw_i16
-; CHECK: and [[REG:w[0-9]+]], w0, #0xffff
-; CHECK: ucvtf s0, [[REG]]
+; CHECK: and w8, w0, #0xffff
+; CHECK: ucvtf s0, w8
 ; CHECK: fcvt  h0, s0
   %conv = uitofp i16 %a to half
   ret half %conv

llvm/test/CodeGen/AArch64/arm64-fast-isel-conversion.ll

@@ -1,4 +1,4 @@
-; RUN: llc -O0 -fast-isel -fast-isel-abort=1 -verify-machineinstrs -mtriple=arm64-apple-darwin -mcpu=cyclone < %s | FileCheck -enable-var-scope %s
+; RUN: llc -O0 -fast-isel -fast-isel-abort=1 -verify-machineinstrs -mtriple=arm64-apple-darwin -mcpu=cyclone < %s | FileCheck %s
 
 ;; Test various conversions.
 define zeroext i32 @trunc_(i8 zeroext %a, i16 zeroext %b, i32 %c, i64 %d) nounwind ssp {
@@ -49,12 +49,13 @@ entry:
 ; CHECK: strh w1, [sp, #12]
 ; CHECK: str w2, [sp, #8]
 ; CHECK: str x3, [sp]
-; CHECK: ldrb [[REG0:w[0-9]+]], [sp, #15]
-; CHECK: strh [[REG0]], [sp, #12]
-; CHECK: ldrh [[REG1:w[0-9]+]], [sp, #12]
-; CHECK: str [[REG1]], [sp, #8]
-; CHECK: ldr w[[REG2:[0-9]+]], [sp, #8]
-; CHECK: str x[[REG2]], [sp]
+; CHECK: ldrb w8, [sp, #15]
+; CHECK: strh w8, [sp, #12]
+; CHECK: ldrh w8, [sp, #12]
+; CHECK: str w8, [sp, #8]
+; CHECK: ldr w8, [sp, #8]
+; CHECK: ; kill: def $x8 killed $w8
+; CHECK: str x8, [sp]
 ; CHECK: ldr x0, [sp]
 ; CHECK: ret
   %a.addr = alloca i8, align 1
@@ -104,12 +105,12 @@ entry:
 ; CHECK: strh w1, [sp, #12]
 ; CHECK: str w2, [sp, #8]
 ; CHECK: str x3, [sp]
-; CHECK: ldrsb [[REG0:w[0-9]+]], [sp, #15]
-; CHECK: strh [[REG0]], [sp, #12]
-; CHECK: ldrsh [[REG1:w[0-9]+]], [sp, #12]
-; CHECK: str [[REG1]], [sp, #8]
-; CHECK: ldrsw [[REG2:x[0-9]+]], [sp, #8]
-; CHECK: str [[REG2]], [sp]
+; CHECK: ldrsb w8, [sp, #15]
+; CHECK: strh w8, [sp, #12]
+; CHECK: ldrsh w8, [sp, #12]
+; CHECK: str w8, [sp, #8]
+; CHECK: ldrsw x8, [sp, #8]
+; CHECK: str x8, [sp]
 ; CHECK: ldr x0, [sp]
 ; CHECK: ret
   %a.addr = alloca i8, align 1
@@ -165,8 +166,8 @@ entry:
 define signext i16 @sext_i1_i16(i1 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: sext_i1_i16
-; CHECK: sbfx [[REG:w[0-9]+]], w0, #0, #1
-; CHECK: sxth w0, [[REG]]
+; CHECK: sbfx w8, w0, #0, #1
+; CHECK-NEXT: sxth	w0, w8
   %conv = sext i1 %a to i16
   ret i16 %conv
 }
@@ -175,8 +176,8 @@ entry:
 define signext i8 @sext_i1_i8(i1 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: sext_i1_i8
-; CHECK: sbfx [[REG:w[0-9]+]], w0, #0, #1
-; CHECK: sxtb w0, [[REG]]
+; CHECK: sbfx w8, w0, #0, #1
+; CHECK-NEXT: sxtb w0, w8
   %conv = sext i1 %a to i8
   ret i8 %conv
 }
@@ -239,8 +240,8 @@ entry:
 define float @sitofp_sw_i1(i1 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: sitofp_sw_i1
-; CHECK: sbfx [[REG:w[0-9]+]], w0, #0, #1
-; CHECK: scvtf s0, [[REG]]
+; CHECK: sbfx w8, w0, #0, #1
+; CHECK: scvtf s0, w8
   %conv = sitofp i1 %a to float
   ret float %conv
 }
@@ -249,8 +250,8 @@ entry:
 define float @sitofp_sw_i8(i8 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: sitofp_sw_i8
-; CHECK: sxtb [[REG:w[0-9]+]], w0
-; CHECK: scvtf s0, [[REG]]
+; CHECK: sxtb w8, w0
+; CHECK: scvtf s0, w8
   %conv = sitofp i8 %a to float
   ret float %conv
 }
@@ -303,8 +304,8 @@ entry:
 define float @uitofp_sw_i1(i1 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: uitofp_sw_i1
-; CHECK: and [[REG:w[0-9]+]], w0, #0x1
-; CHECK: ucvtf s0, [[REG]]
+; CHECK: and w8, w0, #0x1
+; CHECK: ucvtf s0, w8
   %conv = uitofp i1 %a to float
   ret float %conv
 }
@@ -373,8 +374,7 @@ entry:
 define zeroext i16 @i64_trunc_i16(i64 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: i64_trunc_i16
-; CHECK: mov x[[TMP:[0-9]+]], x0
-; CHECK: and [[REG2:w[0-9]+]], w[[TMP]], #0xffff{{$}}
+; CHECK: and [[REG2:w[0-9]+]], w0, #0xffff
 ; CHECK: uxth w0, [[REG2]]
   %conv = trunc i64 %a to i16
   ret i16 %conv
@@ -383,8 +383,7 @@ entry:
 define zeroext i8 @i64_trunc_i8(i64 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: i64_trunc_i8
-; CHECK: mov x[[TMP:[0-9]+]], x0
-; CHECK: and [[REG2:w[0-9]+]], w[[TMP]], #0xff{{$}}
+; CHECK: and [[REG2:w[0-9]+]], w0, #0xff
 ; CHECK: uxtb w0, [[REG2]]
   %conv = trunc i64 %a to i8
   ret i8 %conv
@@ -393,8 +392,7 @@ entry:
 define zeroext i1 @i64_trunc_i1(i64 %a) nounwind ssp {
 entry:
 ; CHECK-LABEL: i64_trunc_i1
-; CHECK: mov x[[TMP:[0-9]+]], x0
-; CHECK: and [[REG2:w[0-9]+]], w[[TMP]], #0x1{{$}}
+; CHECK: and [[REG2:w[0-9]+]], w0, #0x1
 ; CHECK: and w0, [[REG2]], #0x1
   %conv = trunc i64 %a to i1
   ret i1 %conv

llvm/test/CodeGen/AArch64/arm64-vcvt_f.ll

@@ -210,10 +210,10 @@ define <4 x float> @test_vcvt_high_f32_f64(<2 x float> %x, <2 x double> %v) noun
 ;
 ; FAST-LABEL: test_vcvt_high_f32_f64:
 ; FAST:       // %bb.0:
+; FAST-NEXT:    // implicit-def: $q2
 ; FAST-NEXT:    mov.16b v2, v0
-; FAST-NEXT:    // implicit-def: $q0
+; FAST-NEXT:    fcvtn2 v2.4s, v1.2d
 ; FAST-NEXT:    mov.16b v0, v2
-; FAST-NEXT:    fcvtn2 v0.4s, v1.2d
 ; FAST-NEXT:    ret
 ;
 ; GISEL-LABEL: test_vcvt_high_f32_f64:
@@ -249,10 +249,10 @@ define <4 x float> @test_vcvtx_high_f32_f64(<2 x float> %x, <2 x double> %v) nou
 ;
 ; FAST-LABEL: test_vcvtx_high_f32_f64:
 ; FAST:       // %bb.0:
+; FAST-NEXT:    // implicit-def: $q2
 ; FAST-NEXT:    mov.16b v2, v0
-; FAST-NEXT:    // implicit-def: $q0
+; FAST-NEXT:    fcvtxn2 v2.4s, v1.2d
 ; FAST-NEXT:    mov.16b v0, v2
-; FAST-NEXT:    fcvtxn2 v0.4s, v1.2d
 ; FAST-NEXT:    ret
 ;
 ; GISEL-LABEL: test_vcvtx_high_f32_f64:
@@ -283,12 +283,17 @@ define i16 @to_half(float %in) {
 ;
 ; FAST-LABEL: to_half:
 ; FAST:       // %bb.0:
-; FAST-NEXT:    fcvt h1, s0
+; FAST-NEXT:    sub sp, sp, #16 // =16
+; FAST-NEXT:    .cfi_def_cfa_offset 16
+; FAST-NEXT:    fcvt h0, s0
 ; FAST-NEXT:    // implicit-def: $w0
-; FAST-NEXT:    fmov s0, w0
-; FAST-NEXT:    mov.16b v0, v1
-; FAST-NEXT:    fmov w0, s0
-; FAST-NEXT:    // kill: def $w1 killed $w0
+; FAST-NEXT:    fmov s1, w0
+; FAST-NEXT:    mov.16b v1, v0
+; FAST-NEXT:    fmov w8, s1
+; FAST-NEXT:    mov w0, w8
+; FAST-NEXT:    str w0, [sp, #12] // 4-byte Folded Spill
+; FAST-NEXT:    mov w0, w8
+; FAST-NEXT:    add sp, sp, #16 // =16
 ; FAST-NEXT:    ret
 ;
 ; GISEL-LABEL: to_half:

llvm/test/CodeGen/AArch64/arm64_32-fastisel.ll

@@ -17,9 +17,8 @@ declare [2 x i32] @callee()
 define void @test_struct_return(i32* %addr) {
 ; CHECK-LABEL: test_struct_return:
 ; CHECK: bl _callee
-; CHECK: x[[COPYX0:[0-9]+]], x0
-; CHECK-DAG: lsr [[HI:x[0-9]+]], x[[COPYX0]], #32
-; CHECK-DAG: str w[[COPYX0]]
+; CHECK-DAG: lsr [[HI:x[0-9]+]], x0, #32
+; CHECK-DAG: str w0
   %res = call [2 x i32] @callee()
   %res.0 = extractvalue [2 x i32] %res, 0
   store i32 %res.0, i32* %addr

llvm/test/CodeGen/AArch64/arm64_32-null.ll

@@ -13,12 +13,11 @@ define void @test_store(i8** %p) {
 define void @test_phi(i8** %p) {
 ; CHECK-LABEL: test_phi:
 ; CHECK: mov [[R1:x[0-9]+]], xzr
-; CHECK: str [[R1]], [sp, #8]
+; CHECK: str [[R1]], [sp]
 ; CHECK: b [[BB:LBB[0-9_]+]]
 ; CHECK: [[BB]]:
-; CHECK: ldr x0, [sp, #8]
-; CHECK: mov w8, w0
-; CHECK: str w8, [x{{.*}}]
+; CHECK: ldr x0, [sp]
+; CHECK: str w0, [x{{.*}}]
 
 bb0:
   br label %bb1

llvm/test/CodeGen/AArch64/br-cond-not-merge.ll

@@ -64,9 +64,9 @@ bb3:
 ; OPT: b.gt [[L:\.LBB[0-9_]+]]
 ; OPT: tbz w1, #0, [[L]]
 ;
-; NOOPT: str w1, [sp, #[[SLOT2:[0-9]+]]]
 ; NOOPT: subs w{{[0-9]+}}, w{{[0-9]+}}, #0
 ; NOOPT: cset [[R1:w[0-9]+]], gt
+; NOOPT: str w1, [sp, #[[SLOT2:[0-9]+]]]
 ; NOOPT: str [[R1]], [sp, #[[SLOT1:[0-9]+]]]
 ; NOOPT: b .LBB
 ; NOOPT: ldr [[R2:w[0-9]+]], [sp, #[[SLOT1]]]