[llvm] 7e9153e - PowerPC: Don't lower SELECT_CC to PPCISD::FSEL on SPE

[Justin Hibbits via llvm-commits]

Author: Justin Hibbits
Date: 2020-07-31T22:52:47-05:00
New Revision: 7e9153e940e21a937ff3a0e7425eb1b24bd1bb76

URL: https://github.com/llvm/llvm-project/commit/7e9153e940e21a937ff3a0e7425eb1b24bd1bb76
DIFF: https://github.com/llvm/llvm-project/commit/7e9153e940e21a937ff3a0e7425eb1b24bd1bb76.diff

LOG: PowerPC: Don't lower SELECT_CC to PPCISD::FSEL on SPE

SPE doesn't have a fsel instruction, so don't try to lower to it.

This fixes a "Cannot select: tN: f64 = PPCISD::FSEL tX, tY, tZ" error.

Reviewed By: #powerpc, lkail
Differential Revision: https://reviews.llvm.org/D77773

Added: 
    llvm/test/CodeGen/PowerPC/spe-fastmath.ll

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

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 69afed8fb41a..85f1630d8e22 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -7797,9 +7797,9 @@ SDValue PPCTargetLowering::LowerTRUNCATEVector(SDValue Op,
 /// LowerSELECT_CC - Lower floating point select_cc's into fsel instruction when
 /// possible.
 SDValue PPCTargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const {
-  // Not FP? Not a fsel.
+  // Not FP, or using SPE? Not a fsel.
   if (!Op.getOperand(0).getValueType().isFloatingPoint() ||
-      !Op.getOperand(2).getValueType().isFloatingPoint())
+      !Op.getOperand(2).getValueType().isFloatingPoint() || Subtarget.hasSPE())
     return Op;
 
   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();

diff  --git a/llvm/test/CodeGen/PowerPC/spe-fastmath.ll b/llvm/test/CodeGen/PowerPC/spe-fastmath.ll
new file mode 100644
index 000000000000..d2b83f7ee1da
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/spe-fastmath.ll
@@ -0,0 +1,31 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -verify-machineinstrs < %s -mtriple=powerpc-unknown-linux-gnu \
+; RUN:   -mattr=+spe |  FileCheck %s
+
+define void @no_fsel(i32 %e) #0 {
+; CHECK-LABEL: no_fsel:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    li 4, .LCPI0_0 at l
+; CHECK-NEXT:    lis 5, .LCPI0_0 at ha
+; CHECK-NEXT:    evlddx 4, 5, 4
+; CHECK-NEXT:    efdcfui 3, 3
+; CHECK-NEXT:    efdmul 5, 3, 3
+; CHECK-NEXT:    efdcmpeq 0, 5, 4
+; CHECK-NEXT:    ble 0, .LBB0_2
+; CHECK-NEXT:  # %bb.1: # %entry
+; CHECK-NEXT:    evor 3, 4, 4
+; CHECK-NEXT:  .LBB0_2: # %entry
+; CHECK-NEXT:    efdctsiz 3, 3
+; CHECK-NEXT:    sth 3, 0(3)
+; CHECK-NEXT:    blr
+entry:
+  %conv = uitofp i32 %e to double
+  %mul = fmul double %conv, %conv
+  %tobool = fcmp une double %mul, 0.000000e+00
+  %cond = select i1 %tobool, double %conv, double 0.000000e+00
+  %conv3 = fptosi double %cond to i16
+  store i16 %conv3, i16* undef
+  ret void
+}
+
+attributes #0 = { "no-infs-fp-math"="true" "no-nans-fp-math"="true" }