[llvm] 4a22652 - [PowerPC] Fixed the crash due to early if conversion with fixed CR fields

[Victor Huang via llvm-commits]

Author: Victor Huang
Date: 2021-09-07T10:51:03-05:00
New Revision: 4a226529e2cf73be57fb45f511b708414ec3427d

URL: https://github.com/llvm/llvm-project/commit/4a226529e2cf73be57fb45f511b708414ec3427d
DIFF: https://github.com/llvm/llvm-project/commit/4a226529e2cf73be57fb45f511b708414ec3427d.diff

LOG: [PowerPC] Fixed the crash due to early if conversion with fixed CR fields

This patch adds a fix to do early if conversion to select when
conditional branch not using physical register to prevent the crash when
expanding ISEL instruction.

Reviewed By: lei, kamaub, PowerPC

Differential revision: https://reviews.llvm.org/D108302

Added: 
    llvm/test/CodeGen/PowerPC/ifcvt_cr_field.ll

Modified: 
    llvm/lib/Target/PowerPC/PPCInstrInfo.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp b/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
index c74b6bcf4287..0fbb1e95669c 100644
--- a/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
+++ b/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
@@ -1541,6 +1541,11 @@ bool PPCInstrInfo::canInsertSelect(const MachineBasicBlock &MBB,
   if (Cond[1].getReg() == PPC::CTR || Cond[1].getReg() == PPC::CTR8)
     return false;
 
+  // If the conditional branch uses a physical register, then it cannot be
+  // turned into a select.
+  if (Register::isPhysicalRegister(Cond[1].getReg()))
+    return false;
+
   // Check register classes.
   const MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
   const TargetRegisterClass *RC =

diff  --git a/llvm/test/CodeGen/PowerPC/ifcvt_cr_field.ll b/llvm/test/CodeGen/PowerPC/ifcvt_cr_field.ll
new file mode 100644
index 000000000000..1d4e865d2c06
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/ifcvt_cr_field.ll
@@ -0,0 +1,64 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr9 -verify-machineinstrs | FileCheck %s
+; RUN: llc < %s -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr9 -verify-machineinstrs | FileCheck %s
+; RUN: llc < %s -mtriple=powerpc64-unknown-aix -mcpu=pwr9 -verify-machineinstrs | FileCheck %s --check-prefix=CHECK-AIX-64
+; RUN: llc < %s -mtriple=powerpc-unknown-aix -mcpu=pwr9 -verify-machineinstrs | FileCheck %s --check-prefix=CHECK-AIX-32
+
+define dso_local signext i32 @test(<4 x i32> %a, <4 x i32> %b, <4 x i32> %c) local_unnamed_addr {
+; CHECK-LABEL: test:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    vcmpgtsw. 2, 2, 3
+; CHECK-NEXT:    bge 6, .LBB0_2
+; CHECK-NEXT:  # %bb.1: # %land.rhs
+; CHECK-NEXT:    vcmpgtsw. 2, 4, 3
+; CHECK-NEXT:    mfocrf 3, 2
+; CHECK-NEXT:    rlwinm 3, 3, 25, 31, 31
+; CHECK-NEXT:    clrldi 3, 3, 32
+; CHECK-NEXT:    blr
+; CHECK-NEXT:  .LBB0_2:
+; CHECK-NEXT:    li 3, 0
+; CHECK-NEXT:    blr
+;
+; CHECK-AIX-64-LABEL: test:
+; CHECK-AIX-64:       # %bb.0: # %entry
+; CHECK-AIX-64-NEXT:    vcmpgtsw. 2, 2, 3
+; CHECK-AIX-64-NEXT:    bge 6, L..BB0_2
+; CHECK-AIX-64-NEXT:  # %bb.1: # %land.rhs
+; CHECK-AIX-64-NEXT:    vcmpgtsw. 2, 4, 3
+; CHECK-AIX-64-NEXT:    mfocrf 3, 2
+; CHECK-AIX-64-NEXT:    rlwinm 3, 3, 25, 31, 31
+; CHECK-AIX-64-NEXT:    clrldi 3, 3, 32
+; CHECK-AIX-64-NEXT:    blr
+; CHECK-AIX-64-NEXT:  L..BB0_2:
+; CHECK-AIX-64-NEXT:    li 3, 0
+; CHECK-AIX-64-NEXT:    blr
+;
+; CHECK-AIX-32-LABEL: test:
+; CHECK-AIX-32:       # %bb.0: # %entry
+; CHECK-AIX-32-NEXT:    vcmpgtsw. 2, 2, 3
+; CHECK-AIX-32-NEXT:    bge 6, L..BB0_2
+; CHECK-AIX-32-NEXT:  # %bb.1: # %land.rhs
+; CHECK-AIX-32-NEXT:    vcmpgtsw. 2, 4, 3
+; CHECK-AIX-32-NEXT:    mfocrf 3, 2
+; CHECK-AIX-32-NEXT:    rlwinm 3, 3, 25, 31, 31
+; CHECK-AIX-32-NEXT:    blr
+; CHECK-AIX-32-NEXT:  L..BB0_2:
+; CHECK-AIX-32-NEXT:    li 3, 0
+; CHECK-AIX-32-NEXT:    blr
+entry:
+  %0 = tail call i32 @llvm.ppc.altivec.vcmpgtsw.p(i32 2, <4 x i32> %a, <4 x i32> %b)
+  %tobool.not = icmp eq i32 %0, 0
+  br i1 %tobool.not, label %land.end, label %land.rhs
+
+land.rhs:                                         ; preds = %entry
+  %1 = tail call i32 @llvm.ppc.altivec.vcmpgtsw.p(i32 2, <4 x i32> %c, <4 x i32> %b)
+  %tobool1 = icmp ne i32 %1, 0
+  %phi.cast = zext i1 %tobool1 to i32
+  br label %land.end
+
+land.end:                                         ; preds = %land.rhs, %entry
+  %2 = phi i32 [ 0, %entry ], [ %phi.cast, %land.rhs ]
+  ret i32 %2
+}
+
+declare i32 @llvm.ppc.altivec.vcmpgtsw.p(i32, <4 x i32>, <4 x i32>)