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+.file "ilogbl.s"
+
+// Copyright (c) 2000, 2001, Intel Corporation
+// All rights reserved.
+// 
+// Contributed 2/2/2000 by John Harrison, Ted Kubaska, Bob Norin, Shane Story,
+// and Ping Tak Peter Tang of the Computational Software Lab, Intel Corporation.
+// 
+// WARRANTY DISCLAIMER
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS 
+// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
+// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 
+// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING
+// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+// 
+// Intel Corporation is the author of this code, and requests that all
+// problem reports or change requests be submitted to it directly at 
+// http://developer.intel.com/opensource.
+//
+// History
+//==============================================================
+// 2/03/00  Initial version
+// 5/26/00  Fix bug when x a double-extended denormal; 
+//          if x=0 call error routine, per C9X
+// 8/15/00  Bundle added after call to __libm_error_support to properly
+//          set [the previously overwritten] GR_Parameter_RESULT.
+// 1/20/01  Fixed result for x=0
+
+.align 32
+.global ilogbl#
+
+.section .text
+.proc  ilogbl#
+.align 32
+
+// API
+//==============================================================
+// int = ilogbl(double_extended)
+
+// Overview of operation
+//==============================================================
+// ilogbl computes log2(x) as an int
+// and returns it in r8
+
+// ilogbl is similar to logbl but differs in the  following ways:
+//         +-inf
+//            ilogbl: returns INT_MAX
+//             logbl: returns +inf
+//         Nan  returns FP_ILOGBNAN (which is either INT_MAX or INT_MIN)
+//            ilogbl: returns INT_MAX (7fffffff)
+//             logbl: returns QNAN (quieted SNAN)
+//         0    returns FP_ILOGB0 (which is either INT_MIN or -INT_MAX)
+//            ilogbl: returns INT_MIN (80000000)
+//             logbl: returns -inf
+
+// Registers used
+//==============================================================
+
+// general local registers: 
+// ar.pfs r32
+// r33 -> r37
+// r38 -> r41 used as parameters to error path
+
+// predicate registers used: 
+// p6 - x nan, inf
+// p7 - x 0
+// p8 - x norm, unorm
+// p9 - x unorm
+
+// floating-point registers used: 
+// f8 - f10
+
+#include "libm_support.h"
+
+GR_SAVE_PFS         = r32
+GR_SAVE_B0          = r34
+GR_SAVE_GP          = r35
+GR_Parameter_X      = r38
+GR_Parameter_Y      = r39
+GR_Parameter_RESULT = r40
+GR_Parameter_TAG    = r41
+
+FR_X                = f8
+FR_Y                = f0
+FR_RESULT           = f0
+
+
+ilogbl: 
+
+// Form signexp of 2^64 in case need to scale denormal
+{ .mmf
+      alloc          r32=ar.pfs,1,5,4,0
+(p0)  mov      r37 = 0x1003f
+(p0)  fnorm    f9 = f8 ;;
+}
+
+// Form 2^64 in case need to scale denormal
+{ .mfi
+(p0)  setf.exp f10 = r37
+(p0)  fclass.m.unc p7, p8 = f8, 0xe3        
+(p0)  mov      r34 = 0xffff ;;
+}
+
+// qnan snan inf norm     unorm 0 -+
+// 1    1    1   0        0     0 11
+// e                      3
+// X ZERO, returns INT_MIN
+// X INF or NAN, returns INT_MAX
+
+{ .mfi
+(p0)  mov      r35 = 0x1ffff
+(p8)    fclass.m.unc p6, p8 = f8, 0x07
+	nop.i 999 ;;
+}
+{ .mlx
+	nop.m 999
+(p7)    movl r8 = 0x000000007fffffff ;;       
+}
+
+{ .mib
+	nop.m 999
+	nop.i 999
+(p6)    br.cond.spnt  L(ILOGB_ZERO) ;;
+}
+
+// Test for denormal
+{ .mfi
+	nop.m 999
+(p8)    fclass.m.unc p9, p0 = f9, 0x0b        
+	nop.i 999 ;;
+}
+
+L(ILOGB_COMMON):
+// X NORMAL returns true exponent
+{ .mmi
+	nop.m 999 
+(p8)    getf.exp r33 = f9
+	nop.i 999 ;;
+}
+
+// If denormal add 64 to exponent bias for scaling
+{ .mfb
+(p9)    add     r34 = 64, r34   
+	nop.f 999 
+(p9)    br.cond.spnt  L(ILOGB_DENORM) ;;
+}
+
+{ .mmi
+(p8)    and      r36 = r35, r33
+	nop.m 999
+	nop.i 999 ;;
+}
+
+{ .mib
+(p8)    sub r8 = r36, r34                  
+	nop.i 999
+(p0)    br.ret.sptk    b0 ;;                     
+}
+
+L(ILOGB_DENORM):
+// Here if x denormal
+// Form x * 2^64 which is normal
+// Return to common code
+{ .mfb
+        cmp.eq p8,p9 = r0,r0
+        fmpy f9 = f9, f10
+        br.cond.sptk  L(ILOGB_COMMON) ;;
+}
+
+// X ZERO
+// return INT_MIN, call error support
+L(ILOGB_ZERO): 
+{.mlx
+      mov            GR_Parameter_TAG = 156
+(p6)  movl r33 = 0x0000000080000000 ;;
+};;
+.endp ilogbl
+ASM_SIZE_DIRECTIVE(ilogbl)
+
+.proc __libm_error_region
+__libm_error_region:
+.prologue
+{ .mfi
+        add   GR_Parameter_Y=-32,sp             // Parameter 2 value
+        nop.f 0
+.save   ar.pfs,GR_SAVE_PFS
+        mov  GR_SAVE_PFS=ar.pfs                 // Save ar.pfs
+}
+{ .mfi
+.fframe 64
+        add sp=-64,sp                           // Create new stack
+        nop.f 0
+        mov GR_SAVE_GP=gp                       // Save gp
+};;
+{ .mmi
+        stfe [GR_Parameter_Y] = FR_Y,16         // Save Parameter 2 on stack
+        add GR_Parameter_X = 16,sp              // Parameter 1 address
+.save   b0, GR_SAVE_B0
+        mov GR_SAVE_B0=b0                       // Save b0
+};;
+.body
+{ .mib
+        stfe [GR_Parameter_X] = FR_X            // Store Parameter 1 on stack
+        add   GR_Parameter_RESULT = 0,GR_Parameter_Y
+        nop.b 0                                 // Parameter 3 address
+}
+{ .mib
+        stfe [GR_Parameter_Y] = FR_RESULT      // Store Parameter 3 on stack
+        add   GR_Parameter_Y = -16,GR_Parameter_Y
+        br.call.sptk b0=__libm_error_support#  // Call error handling function
+};;
+{ .mmi
+        nop.m 0
+        nop.m 0
+        add   GR_Parameter_RESULT = 48,sp
+};;
+{ .mmi
+        mov   r8 = r33                         // Store result
+.restore sp
+        add   sp = 64,sp                       // Restore stack pointer
+        mov   b0 = GR_SAVE_B0                  // Restore return address
+};;
+{ .mib
+        mov   gp = GR_SAVE_GP                  // Restore gp
+        mov   ar.pfs = GR_SAVE_PFS             // Restore ar.pfs
+        br.ret.sptk     b0                     // Return
+};;
+
+.endp __libm_error_region
+ASM_SIZE_DIRECTIVE(__libm_error_region)
+
+.type   __libm_error_support#,@function
+.global __libm_error_support#