[PowerPC] Handle selection of compare instructions in fast-isel.

Mostly trivial patch adding support for compares.  The meat of the
work was added with the branch support.

llvm-svn: 189639

2 files changed, 307 insertions, 0 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCFastISel.cpp b/llvm/lib/Target/PowerPC/PPCFastISel.cpp
index 14a4b31710b..aeda78bf6b9 100644
--- a/llvm/lib/Target/PowerPC/PPCFastISel.cpp
+++ b/llvm/lib/Target/PowerPC/PPCFastISel.cpp
@@ -108,6 +108,7 @@ class PPCFastISel : public FastISel {
     bool SelectStore(const Instruction *I);
     bool SelectBranch(const Instruction *I);
     bool SelectIndirectBr(const Instruction *I);
+    bool SelectCmp(const Instruction *I);
     bool SelectBinaryIntOp(const Instruction *I, unsigned ISDOpcode);
     bool SelectRet(const Instruction *I);
     bool SelectIntExt(const Instruction *I);
@@ -1065,6 +1066,23 @@ bool PPCFastISel::SelectIndirectBr(const Instruction *I) {
   return true;
 }
 
+// Attempt to fast-select a compare instruction.
+bool PPCFastISel::SelectCmp(const Instruction *I) {
+  const CmpInst *CI = cast<CmpInst>(I);
+  Optional<PPC::Predicate> OptPPCPred = getComparePred(CI->getPredicate());
+  if (!OptPPCPred)
+    return false;
+
+  unsigned CondReg = createResultReg(&PPC::CRRCRegClass);
+
+  if (!PPCEmitCmp(CI->getOperand(0), CI->getOperand(1), CI->isUnsigned(),
+                  CondReg))
+    return false;
+
+  UpdateValueMap(I, CondReg);
+  return true;
+}
+
 // Attempt to fast-select an integer extend instruction.
 bool PPCFastISel::SelectIntExt(const Instruction *I) {
   Type *DestTy = I->getType();
diff --git a/llvm/test/CodeGen/PowerPC/fast-isel-cmp-imm.ll b/llvm/test/CodeGen/PowerPC/fast-isel-cmp-imm.ll
new file mode 100644
index 00000000000..33f7a79783c
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/fast-isel-cmp-imm.ll
@@ -0,0 +1,289 @@
+; RUN: llc < %s -O0 -verify-machineinstrs -fast-isel-abort -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr7 | FileCheck %s --check-prefix=ELF64
+
+define void @t1a(float %a) uwtable ssp {
+entry:
+; ELF64: t1a
+  %cmp = fcmp oeq float %a, 0.000000e+00
+; ELF64: addis
+; ELF64: lfs
+; ELF64: fcmpu
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+declare void @foo()
+
+define void @t1b(float %a) uwtable ssp {
+entry:
+; ELF64: t1b
+  %cmp = fcmp oeq float %a, -0.000000e+00
+; ELF64: addis
+; ELF64: lfs
+; ELF64: fcmpu
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t2a(double %a) uwtable ssp {
+entry:
+; ELF64: t2a
+  %cmp = fcmp oeq double %a, 0.000000e+00
+; ELF64: addis
+; ELF64: lfd
+; ELF64: fcmpu
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t2b(double %a) uwtable ssp {
+entry:
+; ELF64: t2b
+  %cmp = fcmp oeq double %a, -0.000000e+00
+; ELF64: addis
+; ELF64: lfd
+; ELF64: fcmpu
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t4(i8 signext %a) uwtable ssp {
+entry:
+; ELF64: t4
+  %cmp = icmp eq i8 %a, -1
+; ELF64: extsb
+; ELF64: cmpwi
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t5(i8 zeroext %a) uwtable ssp {
+entry:
+; ELF64: t5
+  %cmp = icmp eq i8 %a, 1
+; ELF64: extsb
+; ELF64: cmpwi
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t6(i16 signext %a) uwtable ssp {
+entry:
+; ELF64: t6
+  %cmp = icmp eq i16 %a, -1
+; ELF64: extsh
+; ELF64: cmpwi
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t7(i16 zeroext %a) uwtable ssp {
+entry:
+; ELF64: t7
+  %cmp = icmp eq i16 %a, 1
+; ELF64: extsh
+; ELF64: cmpwi
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t8(i32 %a) uwtable ssp {
+entry:
+; ELF64: t8
+  %cmp = icmp eq i32 %a, -1
+; ELF64: cmpwi
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t9(i32 %a) uwtable ssp {
+entry:
+; ELF64: t9
+  %cmp = icmp eq i32 %a, 1
+; ELF64: cmpwi
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t10(i32 %a) uwtable ssp {
+entry:
+; ELF64: t10
+  %cmp = icmp eq i32 %a, 384
+; ELF64: cmpwi
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t11(i32 %a) uwtable ssp {
+entry:
+; ELF64: t11
+  %cmp = icmp eq i32 %a, 4096
+; ELF64: cmpwi
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t12(i8 %a) uwtable ssp {
+entry:
+; ELF64: t12
+  %cmp = icmp ugt i8 %a, -113
+; ELF64: rlwinm
+; ELF64: cmplwi
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t13() nounwind ssp {
+entry:
+; ELF64: t13
+  %cmp = icmp slt i32 -123, -2147483648
+; ELF64: li
+; ELF64: lis
+; ELF64: cmpw
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  ret void
+
+if.end:                                           ; preds = %entry
+  ret void
+}
+
+define void @t14(i64 %a) uwtable ssp {
+entry:
+; ELF64: t14
+  %cmp = icmp eq i64 %a, -1
+; ELF64: cmpdi
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t15(i64 %a) uwtable ssp {
+entry:
+; ELF64: t15
+  %cmp = icmp eq i64 %a, 1
+; ELF64: cmpdi
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t16(i64 %a) uwtable ssp {
+entry:
+; ELF64: t16
+  %cmp = icmp eq i64 %a, 384
+; ELF64: cmpdi
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+define void @t17(i64 %a) uwtable ssp {
+entry:
+; ELF64: t17
+  %cmp = icmp eq i64 %a, 32768
+; Extra operand so we don't match on cmpdi.
+; ELF64: cmpd {{[0-9]+}}
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @foo()
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+