From c072c50d24235f40c9d2f0b63caf1db580d36a20 Mon Sep 17 00:00:00 2001
From: Simon Dardis <simon.dardis@imgtec.com>
Date: Tue, 4 Oct 2016 10:35:07 +0000
Subject: [PATCH] [mips][fastisel] Consider soft-float an unsupported floating
 point mode

Treat soft-float as unsupported for fast-isel. Additionally, ensure we check
that lowering f32 arguments also considers the case of soft-float mode.

Reviewers: ehostunreach, vkalintiris, zoran.jovanovic

Differential Review: https://reviews.llvm.org/D24505


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283209 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/Mips/MipsFastISel.cpp                      |  8 ++++++--
 .../Mips/Fast-ISel/fast-isel-softfloat-lower-args.ll  | 11 +++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)
 create mode 100644 test/CodeGen/Mips/Fast-ISel/fast-isel-softfloat-lower-args.ll

diff --git a/lib/Target/Mips/MipsFastISel.cpp b/lib/Target/Mips/MipsFastISel.cpp
index 94531642492..1581bc9c58a 100644
--- a/lib/Target/Mips/MipsFastISel.cpp
+++ b/lib/Target/Mips/MipsFastISel.cpp
@@ -216,7 +216,7 @@ public:
                         !Subtarget->inMicroMipsMode() && Subtarget->hasMips32();
     TargetSupported =
         ISASupported && TM.isPositionIndependent() && getABI().IsO32();
-    UnsupportedFPMode = Subtarget->isFP64bit();
+    UnsupportedFPMode = Subtarget->isFP64bit() || Subtarget->useSoftFloat();
   }
 
   unsigned fastMaterializeAlloca(const AllocaInst *AI) override;
@@ -1365,6 +1365,10 @@ bool MipsFastISel::fastLowerArguments() {
       break;
 
     case MVT::f32:
+      if (UnsupportedFPMode) {
+        DEBUG(dbgs() << ".. .. gave up (UnsupportedFPMode)\n");
+        return false;
+      }
       if (NextFGR32 == FGR32ArgRegs.end()) {
         DEBUG(dbgs() << ".. .. gave up (ran out of FGR32 arguments)\n");
         return false;
@@ -1381,7 +1385,7 @@ bool MipsFastISel::fastLowerArguments() {
 
     case MVT::f64:
       if (UnsupportedFPMode) {
-        DEBUG(dbgs() << ".. .. gave up (UnsupportedFPMode\n");
+        DEBUG(dbgs() << ".. .. gave up (UnsupportedFPMode)\n");
         return false;
       }
       if (NextAFGR64 == AFGR64ArgRegs.end()) {
diff --git a/test/CodeGen/Mips/Fast-ISel/fast-isel-softfloat-lower-args.ll b/test/CodeGen/Mips/Fast-ISel/fast-isel-softfloat-lower-args.ll
new file mode 100644
index 00000000000..24161ca8238
--- /dev/null
+++ b/test/CodeGen/Mips/Fast-ISel/fast-isel-softfloat-lower-args.ll
@@ -0,0 +1,11 @@
+; RUN: not llc -march=mipsel -mcpu=mips32r2 -mattr=+soft-float \
+; RUN:         -O0 -fast-isel-abort=3 -relocation-model=pic < %s
+
+; Test that FastISel aborts instead of trying to lower arguments for soft-float.
+
+define void @__signbit(double %__x) {
+entry:
+  %__x.addr = alloca double, align 8
+  store double %__x, double* %__x.addr, align 8
+  ret void
+}