[RISCV] Codegen support for RV32D floating point comparison operations

Also add double-prevoius-failure.ll which captures a test case that at one
point triggered a compiler crash, while developing calling convention support
for f64 on RV32D with soft-float ABI.

llvm-svn: 329877
diff --git a/llvm/test/CodeGen/RISCV/double-previous-failure.ll b/llvm/test/CodeGen/RISCV/double-previous-failure.ll
new file mode 100644
index 0000000..3884049
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/double-previous-failure.ll
@@ -0,0 +1,71 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=riscv32 -mattr=+d -verify-machineinstrs < %s \
+; RUN:   | FileCheck -check-prefix=RV32IFD %s
+
+define double @test(double %a) nounwind {
+; RV32IFD-LABEL: test:
+; RV32IFD:       # %bb.0:
+; RV32IFD-NEXT:    ret
+  ret double %a
+}
+
+; This previously failed complaining of multiple vreg defs due to an ABI
+; lowering issue.
+
+define i32 @main() nounwind {
+; RV32IFD-LABEL: main:
+; RV32IFD:       # %bb.0: # %entry
+; RV32IFD-NEXT:    addi sp, sp, -16
+; RV32IFD-NEXT:    sw ra, 12(sp)
+; RV32IFD-NEXT:    lui a0, %hi(test)
+; RV32IFD-NEXT:    addi a2, a0, %lo(test)
+; RV32IFD-NEXT:    lui a0, %hi(.LCPI1_0)
+; RV32IFD-NEXT:    addi a0, a0, %lo(.LCPI1_0)
+; RV32IFD-NEXT:    fld ft0, 0(a0)
+; RV32IFD-NEXT:    fsd ft0, 0(sp)
+; RV32IFD-NEXT:    lw a0, 0(sp)
+; RV32IFD-NEXT:    lw a1, 4(sp)
+; RV32IFD-NEXT:    jalr a2
+; RV32IFD-NEXT:    sw a0, 0(sp)
+; RV32IFD-NEXT:    sw a1, 4(sp)
+; RV32IFD-NEXT:    fld ft0, 0(sp)
+; RV32IFD-NEXT:    lui a0, %hi(.LCPI1_1)
+; RV32IFD-NEXT:    addi a0, a0, %lo(.LCPI1_1)
+; RV32IFD-NEXT:    fld ft1, 0(a0)
+; RV32IFD-NEXT:    flt.d a0, ft0, ft1
+; RV32IFD-NEXT:    bnez a0, .LBB1_3
+; RV32IFD-NEXT:  # %bb.1: # %entry
+; RV32IFD-NEXT:    lui a0, %hi(.LCPI1_2)
+; RV32IFD-NEXT:    addi a0, a0, %lo(.LCPI1_2)
+; RV32IFD-NEXT:    fld ft1, 0(a0)
+; RV32IFD-NEXT:    flt.d a0, ft1, ft0
+; RV32IFD-NEXT:    xori a0, a0, 1
+; RV32IFD-NEXT:    beqz a0, .LBB1_3
+; RV32IFD-NEXT:  # %bb.2: # %if.end
+; RV32IFD-NEXT:    lui a0, %hi(exit)
+; RV32IFD-NEXT:    addi a1, a0, %lo(exit)
+; RV32IFD-NEXT:    mv a0, zero
+; RV32IFD-NEXT:    jalr a1
+; RV32IFD-NEXT:  .LBB1_3: # %if.then
+; RV32IFD-NEXT:    lui a0, %hi(abort)
+; RV32IFD-NEXT:    addi a0, a0, %lo(abort)
+; RV32IFD-NEXT:    jalr a0
+entry:
+  %call = call double @test(double 2.000000e+00)
+  %cmp = fcmp olt double %call, 2.400000e-01
+  %cmp2 = fcmp ogt double %call, 2.600000e-01
+  %or.cond = or i1 %cmp, %cmp2
+  br i1 %or.cond, label %if.then, label %if.end
+
+if.then:
+  call void @abort()
+  unreachable
+
+if.end:
+  call void @exit(i32 0)
+  unreachable
+}
+
+declare void @abort()
+
+declare void @exit(i32)