Fix a problem with fast-isel return values introduced in r134018.

We would put the return value from long double functions in the wrong
register.

This fixes gcc.c-torture/execute/conversion.c

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134205 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index cdaa29216b7849b5e42d7cc3a299f9c66a2dd208..21e163a300545d9e931015b4ea6b8d732e71d504 100644 (file)
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -1849,9 +1849,10 @@ bool X86FastISel::DoSelectCall(const Instruction *I, const char *MemIntName) {
     // out as F80 and use a truncate to move it from fp stack reg to xmm reg.
     if ((RVLocs[i].getLocReg() == X86::ST0 ||
          RVLocs[i].getLocReg() == X86::ST1)) {
-      if (isScalarFPTypeInSSEReg(RVLocs[i].getValVT()))
+      if (isScalarFPTypeInSSEReg(RVLocs[i].getValVT())) {
         CopyVT = MVT::f80;
-      CopyReg = createResultReg(X86::RFP80RegisterClass);
+        CopyReg = createResultReg(X86::RFP80RegisterClass);
+      }
       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::FpPOP_RETVAL),
               CopyReg);
     } else {

diff --git a/test/CodeGen/X86/fp-stack-O0.ll b/test/CodeGen/X86/fp-stack-O0.ll
new file mode 100644 (file)
index 0000000..b9cb5d7
--- /dev/null
+++ b/test/CodeGen/X86/fp-stack-O0.ll
@@ -0,0 +1,24 @@
+; RUN: llc < %s -O0 | FileCheck %s
+target triple = "x86_64-apple-macosx"
+
+declare x86_fp80 @x1(i32) nounwind
+declare i32 @x2(x86_fp80, x86_fp80) nounwind
+
+; Keep track of the return value.
+; CHECK: test1
+; CHECK: x1
+; Pass arguments on the stack.
+; CHECK-NEXT: movq %rsp, [[RCX:%r..]]
+; Copy constant-pool value.
+; CHECK-NEXT: fldt LCPI
+; CHECK-NEXT: fstpt 16([[RCX]])
+; Copy x1 return value.
+; CHECK-NEXT: fstpt ([[RCX]])
+; CHECK-NEXT: x2
+define i32 @test1() nounwind uwtable ssp {
+entry:
+  %call = call x86_fp80 (...)* bitcast (x86_fp80 (i32)* @x1 to x86_fp80 (...)*)(i32 -1)
+  %call1 = call i32 @x2(x86_fp80 %call, x86_fp80 0xK401EFFFFFFFF00000000)
+  ret i32 %call1
+}
+