From: Kyle Butt <kyle+llvm@iteratee.net>
Date: Wed, 2 Dec 2015 18:58:51 +0000 (+0000)
Subject: [CodeGen]: Fix bad interaction with AntiDep breaking and inline asm.
X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=commitdiff_plain;h=325a79d6e98b9192276abe7421ba491fae199446

[CodeGen]: Fix bad interaction with AntiDep breaking and inline asm.

AggressiveAntiDepBreaker was renaming registers specified by the user
for inline assembly. While this will work for compiler-specified
registers, it won't work for user-specified registers, and at the time
this runs, I don't currently see a way to distinguish them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254532 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/AggressiveAntiDepBreaker.cpp b/lib/CodeGen/AggressiveAntiDepBreaker.cpp
index 845408f15f5..4060db74a9b 100644
--- a/lib/CodeGen/AggressiveAntiDepBreaker.cpp
+++ b/lib/CodeGen/AggressiveAntiDepBreaker.cpp
@@ -364,9 +364,11 @@ void AggressiveAntiDepBreaker::PrescanInstruction(MachineInstr *MI,
 
     // If MI's defs have a special allocation requirement, don't allow
     // any def registers to be changed. Also assume all registers
-    // defined in a call must not be changed (ABI).
+    // defined in a call must not be changed (ABI). Inline assembly may
+    // reference either system calls or the register directly. Skip it until we
+    // can tell user specified registers from compiler-specified.
     if (MI->isCall() || MI->hasExtraDefRegAllocReq() ||
-        TII->isPredicated(MI)) {
+        TII->isPredicated(MI) || MI->isInlineAsm()) {
       DEBUG(if (State->GetGroup(Reg) != 0) dbgs() << "->g0(alloc-req)");
       State->UnionGroups(Reg, 0);
     }
@@ -428,6 +430,7 @@ void AggressiveAntiDepBreaker::ScanInstruction(MachineInstr *MI,
   // If MI's uses have special allocation requirement, don't allow
   // any use registers to be changed. Also assume all registers
   // used in a call must not be changed (ABI).
+  // Inline Assembly register uses also cannot be safely changed.
   // FIXME: The issue with predicated instruction is more complex. We are being
   // conservatively here because the kill markers cannot be trusted after
   // if-conversion:
@@ -443,7 +446,7 @@ void AggressiveAntiDepBreaker::ScanInstruction(MachineInstr *MI,
   // changed.
   bool Special = MI->isCall() ||
     MI->hasExtraSrcRegAllocReq() ||
-    TII->isPredicated(MI);
+    TII->isPredicated(MI) || MI->isInlineAsm();
 
   // Scan the register uses for this instruction and update
   // live-ranges, groups and RegRefs.
diff --git a/test/CodeGen/PowerPC/aantidep-inline-asm-use.ll b/test/CodeGen/PowerPC/aantidep-inline-asm-use.ll
new file mode 100644
index 00000000000..4e7e9775044
--- /dev/null
+++ b/test/CodeGen/PowerPC/aantidep-inline-asm-use.ll
@@ -0,0 +1,308 @@
+; RUN: llc -O2 < %s | FileCheck %s
+; ModuleID = 'bugpoint-reduced-simplified.bc'
+target datalayout = "e-m:e-i64:64-n32:64"
+target triple = "powerpc64le-grtev4-linux-gnu"
+
+; Function Attrs: nounwind
+define void @_ZN10SubProcess19ScrubbedForkAndExecEiPiS0_PNS_7ResultsE() #0 align 2 {
+; CHECK: lis 3, 1234
+; CHECK-NOT: li 3
+; CHECK-NOT: ori 3
+; CHECK-NOT: addi 3
+; CHECK-NOT: addis 3
+; CHECK-NOT: lis 3
+; CHECK: sc
+  br i1 undef, label %1, label %2
+
+; <label>:1                                       ; preds = %0
+  br label %60
+
+; <label>:2                                       ; preds = %0
+  br i1 undef, label %3, label %4
+
+; <label>:3                                       ; preds = %2
+  unreachable
+
+; <label>:4                                       ; preds = %2
+  br i1 undef, label %.lr.ph111, label %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit
+
+.lr.ph111:                                        ; preds = %4
+  br label %5
+
+_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit: ; preds = %12, %4
+  br i1 undef, label %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19.preheader, label %13
+
+; <label>:5                                       ; preds = %12, %.lr.ph111
+  br i1 undef, label %6, label %9
+
+; <label>:6                                       ; preds = %5
+  br i1 undef, label %7, label %8
+
+; <label>:7                                       ; preds = %6
+  unreachable
+
+; <label>:8                                       ; preds = %6
+  br label %12
+
+; <label>:9                                       ; preds = %5
+  br i1 undef, label %10, label %11
+
+; <label>:10                                      ; preds = %9
+  br label %12
+
+; <label>:11                                      ; preds = %9
+  br label %12
+
+; <label>:12                                      ; preds = %11, %10, %8
+  br i1 undef, label %5, label %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit
+
+; <label>:13                                      ; preds = %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit
+  br i1 undef, label %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19.preheader, label %14
+
+; <label>:14                                      ; preds = %13
+  br label %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19.preheader
+
+_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19.preheader: ; preds = %14, %13, %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit
+  br i1 undef, label %_ZN10SubProcess12SafeSyscalls5closeEi.exit.preheader, label %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19._crit_edge
+
+_ZN10SubProcess12SafeSyscalls5closeEi.exit.preheader: ; preds = %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19, %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19.preheader
+  br label %_ZN10SubProcess12SafeSyscalls5closeEi.exit
+
+_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19._crit_edge: ; preds = %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19, %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19.preheader
+  br i1 undef, label %15, label %19
+
+_ZN10SubProcess12SafeSyscalls5closeEi.exit:       ; preds = %_ZN10SubProcess12SafeSyscalls5closeEi.exit, %_ZN10SubProcess12SafeSyscalls5closeEi.exit.preheader
+  br i1 undef, label %_ZN10SubProcess12SafeSyscalls5closeEi.exit, label %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19
+
+_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19: ; preds = %_ZN10SubProcess12SafeSyscalls5closeEi.exit
+  br i1 undef, label %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19._crit_edge, label %_ZN10SubProcess12SafeSyscalls5closeEi.exit.preheader
+
+; <label>:15                                      ; preds = %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19._crit_edge
+  br label %16
+
+; <label>:16                                      ; preds = %17, %15
+  br i1 undef, label %17, label %.critedge.preheader
+
+; <label>:17                                      ; preds = %16
+  br i1 undef, label %16, label %.critedge.preheader
+
+.critedge.preheader:                              ; preds = %17, %16
+  br label %.critedge
+
+.critedge:                                        ; preds = %18, %.critedge.preheader
+  br i1 undef, label %18, label %.critedge8
+
+; <label>:18                                      ; preds = %.critedge
+  br i1 undef, label %.critedge, label %.critedge8
+
+.critedge8:                                       ; preds = %18, %.critedge
+  br label %59
+
+; <label>:19                                      ; preds = %_ZN10SubProcess12SafeSyscalls11sigprocmaskEiPKNS0_15kernel_sigset_tEPS1_.exit19._crit_edge
+  br label %_ZN10SubProcess12SafeSyscalls5closeEi.exit22
+
+_ZN10SubProcess12SafeSyscalls5closeEi.exit22:     ; preds = %_ZN10SubProcess12SafeSyscalls5closeEi.exit22, %19
+  br i1 undef, label %_ZN10SubProcess12SafeSyscalls5closeEi.exit22, label %20
+
+; <label>:20                                      ; preds = %_ZN10SubProcess12SafeSyscalls5closeEi.exit22
+  %21 = alloca i8, i64 undef, align 1
+  br label %.thread.outer
+
+.thread.outer:                                    ; preds = %._crit_edge, %20
+  br label %.thread
+
+.thread:                                          ; preds = %45, %.thread.outer
+  call void @llvm.memset.p0i8.i64(i8* undef, i8 0, i64 56, i32 8, i1 false)
+  store i8* %21, i8** undef, align 8
+  store i32 1073741824, i32* undef, align 8
+  %22 = call { i64, i64, i64, i64, i64, i64, i64 } asm sideeffect "sc\0A\09mfcr $0", "=&{r0},=&{r3},=&{r4},=&{r5},=&{r6},=&{r7},=&{r8},{r0},{r3},{r4},{r5},~{cr0},~{ctr},~{memory},~{r11},~{r12}"(i64 342, i64 80871424, i64 undef, i64 0) #2, !srcloc !1
+  br i1 undef, label %.lr.ph, label %.critedge15.preheader
+
+.critedge15.preheader:                            ; preds = %_ZN10SubProcess12SafeSyscalls7recvmsgEiPNS0_13kernel_msghdrEi.exit.backedge, %.thread
+  br i1 undef, label %.lr.ph93.preheader, label %.critedge15._crit_edge
+
+.lr.ph93.preheader:                               ; preds = %.critedge15.preheader
+  br label %.lr.ph93
+
+.lr.ph:                                           ; preds = %_ZN10SubProcess12SafeSyscalls7recvmsgEiPNS0_13kernel_msghdrEi.exit.backedge, %.thread
+  switch i32 undef, label %.critedge9 [
+    i32 11, label %_ZN10SubProcess12SafeSyscalls7recvmsgEiPNS0_13kernel_msghdrEi.exit.backedge
+    i32 4, label %_ZN10SubProcess12SafeSyscalls7recvmsgEiPNS0_13kernel_msghdrEi.exit.backedge
+  ]
+
+_ZN10SubProcess12SafeSyscalls7recvmsgEiPNS0_13kernel_msghdrEi.exit.backedge: ; preds = %.lr.ph, %.lr.ph
+  br i1 undef, label %.lr.ph, label %.critedge15.preheader
+
+.critedge9:                                       ; preds = %.lr.ph
+  unreachable
+
+.critedge15._crit_edge:                           ; preds = %.critedge15, %.critedge15.preheader
+  br i1 undef, label %35, label %34
+
+.lr.ph93:                                         ; preds = %.critedge15, %.lr.ph93.preheader
+  switch i32 undef, label %33 [
+    i32 0, label %23
+    i32 1, label %23
+    i32 2, label %23
+    i32 3, label %23
+    i32 4, label %23
+    i32 5, label %23
+    i32 6, label %23
+    i32 7, label %23
+    i32 8, label %27
+    i32 9, label %30
+  ]
+
+; <label>:23                                      ; preds = %.lr.ph93, %.lr.ph93, %.lr.ph93, %.lr.ph93, %.lr.ph93, %.lr.ph93, %.lr.ph93, %.lr.ph93
+  br i1 undef, label %24, label %.critedge15
+
+; <label>:24                                      ; preds = %23
+  br i1 undef, label %.critedge15, label %25
+
+; <label>:25                                      ; preds = %24
+  br i1 undef, label %.critedge15, label %26
+
+; <label>:26                                      ; preds = %25
+  unreachable
+
+; <label>:27                                      ; preds = %.lr.ph93
+  br i1 undef, label %.critedge15, label %28
+
+; <label>:28                                      ; preds = %27
+  br i1 undef, label %29, label %.critedge15
+
+; <label>:29                                      ; preds = %28
+  br label %.critedge15
+
+; <label>:30                                      ; preds = %.lr.ph93
+  br i1 undef, label %.critedge15, label %31
+
+; <label>:31                                      ; preds = %30
+  br i1 undef, label %32, label %.critedge15
+
+; <label>:32                                      ; preds = %31
+  br label %.critedge15
+
+; <label>:33                                      ; preds = %.lr.ph93
+  unreachable
+
+.critedge15:                                      ; preds = %32, %31, %30, %29, %28, %27, %25, %24, %23
+  br i1 undef, label %.lr.ph93, label %.critedge15._crit_edge
+
+; <label>:34                                      ; preds = %.critedge15._crit_edge
+  unreachable
+
+; <label>:35                                      ; preds = %.critedge15._crit_edge
+  br i1 undef, label %45, label %36
+
+; <label>:36                                      ; preds = %35
+  br i1 undef, label %37, label %38
+
+; <label>:37                                      ; preds = %36
+  br i1 undef, label %.preheader, label %38
+
+.preheader:                                       ; preds = %37
+  br i1 undef, label %.lr.ph101, label %._crit_edge
+
+.lr.ph101:                                        ; preds = %.preheader
+  br label %39
+
+; <label>:38                                      ; preds = %37, %36
+  unreachable
+
+; <label>:39                                      ; preds = %43, %.lr.ph101
+  br i1 undef, label %40, label %43
+
+; <label>:40                                      ; preds = %39
+  br i1 undef, label %_ZN10SubProcess12SafeSyscalls5fcntlEiil.exit17, label %41
+
+; <label>:41                                      ; preds = %40
+  unreachable
+
+_ZN10SubProcess12SafeSyscalls5fcntlEiil.exit17:   ; preds = %40
+  br i1 undef, label %42, label %_ZN10SubProcess12SafeSyscalls5fcntlEiil.exit
+
+; <label>:42                                      ; preds = %_ZN10SubProcess12SafeSyscalls5fcntlEiil.exit17
+  unreachable
+
+_ZN10SubProcess12SafeSyscalls5fcntlEiil.exit:     ; preds = %_ZN10SubProcess12SafeSyscalls5fcntlEiil.exit17
+  br i1 undef, label %.thread27, label %43
+
+; <label>:43                                      ; preds = %_ZN10SubProcess12SafeSyscalls5fcntlEiil.exit, %39
+  br i1 undef, label %39, label %._crit_edge
+
+.thread27:                                        ; preds = %_ZN10SubProcess12SafeSyscalls5fcntlEiil.exit
+  br label %58
+
+._crit_edge:                                      ; preds = %43, %.preheader
+  br i1 undef, label %.thread.outer, label %44
+
+; <label>:44                                      ; preds = %._crit_edge
+  unreachable
+
+; <label>:45                                      ; preds = %35
+  br i1 undef, label %46, label %.thread
+
+; <label>:46                                      ; preds = %45
+  br i1 undef, label %48, label %47
+
+; <label>:47                                      ; preds = %46
+  unreachable
+
+; <label>:48                                      ; preds = %46
+  br i1 undef, label %55, label %49
+
+; <label>:49                                      ; preds = %48
+  br i1 undef, label %50, label %51
+
+; <label>:50                                      ; preds = %49
+  br label %52
+
+; <label>:51                                      ; preds = %49
+  br label %52
+
+; <label>:52                                      ; preds = %51, %50
+  br label %53
+
+; <label>:53                                      ; preds = %54, %52
+  br i1 undef, label %54, label %.critedge13
+
+; <label>:54                                      ; preds = %53
+  br i1 undef, label %53, label %.critedge13
+
+.critedge13:                                      ; preds = %54, %53
+  br label %58
+
+; <label>:55                                      ; preds = %48
+  br label %56
+
+; <label>:56                                      ; preds = %57, %55
+  br i1 undef, label %57, label %.critedge14
+
+; <label>:57                                      ; preds = %56
+  br i1 undef, label %56, label %.critedge14
+
+.critedge14:                                      ; preds = %57, %56
+  br label %58
+
+; <label>:58                                      ; preds = %.critedge14, %.critedge13, %.thread27
+  br label %59
+
+; <label>:59                                      ; preds = %58, %.critedge8
+  br label %60
+
+; <label>:60                                      ; preds = %59, %1
+  ret void
+}
+
+; Function Attrs: nounwind argmemonly
+declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) #1
+
+attributes #0 = { nounwind "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="pwr8" "target-features"="+altivec,+bpermd,+crypto,+direct-move,+extdiv,+power8-vector,+vsx,-qpx" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind argmemonly }
+attributes #2 = { nounwind }
+
+!llvm.ident = !{!0}
+
+!0 = !{!"clang version google3-trunk (trunk r251807)"}
+!1 = !{i32 -2140527538, i32 -2140527533}