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-rw-r--r--sysdeps/ia64/fpu/s_libm_scalbn.S369
1 files changed, 220 insertions, 149 deletions
diff --git a/sysdeps/ia64/fpu/s_libm_scalbn.S b/sysdeps/ia64/fpu/s_libm_scalbn.S
index fb7ab93ff3..eaccb7de7a 100644
--- a/sysdeps/ia64/fpu/s_libm_scalbn.S
+++ b/sysdeps/ia64/fpu/s_libm_scalbn.S
@@ -21,33 +21,34 @@
// products derived from this software without specific prior written
// permission.
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// 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
+// 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
+// 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.
-//
+// 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
+// problem reports or change requests be submitted to it directly at
// http://www.intel.com/software/products/opensource/libraries/num.htm.
//
// History
//==============================================================
// 02/02/00 Initial version
-// 01/26/01 Scalbn completely reworked and now standalone version
+// 01/26/01 Scalbn completely reworked and now standalone version
// 01/04/02 Added handling for int 32 or 64 bits
// 05/20/02 Cleaned up namespace and sf0 syntax
// 02/10/03 Reordered header: .section, .global, .proc, .align
+// 08/04/03 Improved performance
//
// API
//==============================================================
-// double __libm_scalbn (double x, int n, int int_type)
+// double __libm_scalbn (double x, int n, int int_type)
// input floating point f8 and int n (r33), int int_type (r34)
// output floating point f8
//
@@ -55,27 +56,41 @@
// int_type = 1 if int is 64 bits
//
// Returns x* 2**n using an fma and detects overflow
-// and underflow.
+// and underflow.
//
//
+// Strategy:
+// Compute biased exponent of result exp_Result = N + exp_X
+// Break into ranges:
+// exp_Result > 0x103fe -> Certain overflow
+// exp_Result = 0x103fe -> Possible overflow
+// 0x0fc01 <= exp_Result < 0x103fe -> No over/underflow (main path)
+// 0x0fc01 - 52 <= exp_Result < 0x0fc01 -> Possible underflow
+// exp_Result < 0x0fc01 - 52 -> Certain underflow
FR_Big = f6
FR_NBig = f7
FR_Floating_X = f8
FR_Result = f8
FR_Result2 = f9
-FR_Result3 = f11
-FR_Norm_X = f12
-FR_Two_N = f14
-FR_Two_to_Big = f15
+FR_Result3 = f10
+FR_Norm_X = f11
+FR_Two_N = f12
+GR_neg_ov_limit= r14
GR_N_Biased = r15
GR_Big = r16
GR_NBig = r17
-GR_Scratch = r18
-GR_Scratch1 = r19
+GR_exp_Result = r18
+GR_pos_ov_limit= r19
GR_Bias = r20
GR_N_as_int = r21
+GR_signexp_X = r22
+GR_exp_X = r23
+GR_exp_mask = r24
+GR_max_exp = r25
+GR_min_exp = r26
+GR_min_den_exp = r27
GR_SAVE_B0 = r32
GR_SAVE_GP = r33
@@ -93,242 +108,298 @@ GLOBAL_LIBM_ENTRY(__libm_scalbn)
// Build the exponent Bias
//
{ .mfi
- alloc r32=ar.pfs,3,0,4,0
- fclass.m p7,p0 = FR_Floating_X, 0xe7 //@snan | @qnan | @inf | @zero
- addl GR_Bias = 0x0FFFF,r0
+ getf.exp GR_signexp_X = FR_Floating_X // Get signexp of x
+ fclass.m p6,p0 = FR_Floating_X, 0xe7 // @snan | @qnan | @inf | @zero
+ mov GR_Bias = 0x0ffff
}
-
//
-// Is N zero?
// Normalize x
// Is integer type 32 bits?
//
{ .mfi
- cmp.eq p6,p0 = r33,r0
- fnorm.s1 FR_Norm_X = FR_Floating_X
- cmp.eq p8,p9 = r34,r0
+ mov GR_Big = 35000 // If N this big then certain overflow
+ fnorm.s1 FR_Norm_X = FR_Floating_X
+ cmp.eq p8,p9 = r34,r0
}
;;
// Sign extend N if int is 32 bits
{ .mfi
(p9) mov GR_N_as_int = r33 // Copy N if int is 64 bits
- nop.f 0
+ fclass.m p9,p0 = FR_Floating_X, 0x0b // Test for x=unorm
(p8) sxt4 GR_N_as_int = r33 // Sign extend N if int is 32 bits
}
+{ .mfi
+ mov GR_NBig = -35000 // If N this small then certain underflow
+ nop.f 0
+ mov GR_max_exp = 0x103fe // Exponent of maximum double
+}
+;;
+
+// Create biased exponent for 2**N
+{ .mfi
+ add GR_N_Biased = GR_Bias,GR_N_as_int
+ nop.f 0
+ cmp.ge p7, p0 = GR_N_as_int, GR_Big // Certain overflow?
+}
+{ .mib
+ cmp.le p8, p0 = GR_N_as_int, GR_NBig // Certain underflow?
+ mov GR_min_exp = 0x0fc01 // Exponent of minimum double
+(p9) br.cond.spnt SCALBN_UNORM // Branch if x=unorm
+}
+;;
+
+SCALBN_COMMON:
+// Main path continues. Also return here from x=unorm path.
+// Create 2**N
+.pred.rel "mutex",p7,p8
+{ .mfi
+ setf.exp FR_Two_N = GR_N_Biased
+ nop.f 0
+(p7) mov GR_N_as_int = GR_Big // Limit max N
+}
+{ .mfi
+(p8) mov GR_N_as_int = GR_NBig // Limit min N
+ nop.f 0
+(p8) cmp.eq p7,p0 = r0,r0 // Set p7 if |N| big
+}
;;
//
-// Branch and return special values.
-// Create -35000
-// Create 35000
+// Create biased exponent for 2**N for N big
+// Is N zero?
//
{ .mfi
- addl GR_Big = 35000,r0
+(p7) add GR_N_Biased = GR_Bias,GR_N_as_int
nop.f 0
- add GR_N_Biased = GR_Bias,GR_N_as_int
+ cmp.eq.or p6,p0 = r33,r0
}
-{ .mfb
- addl GR_NBig = -35000,r0
-(p7) fma.d.s0 FR_Result = FR_Floating_X,f1, f0
-(p7) br.ret.spnt b0
-};;
+{ .mfi
+ mov GR_pos_ov_limit = 0x103ff // Exponent for positive overflow
+ nop.f 0
+ mov GR_exp_mask = 0x1ffff // Exponent mask
+}
+;;
//
-// Build the exponent Bias
-// Return x when N = 0
+// Create 2**N for N big
+// Return x when N = 0 or X = Nan, Inf, Zero
//
{ .mfi
- setf.exp FR_Two_N = GR_N_Biased
+(p7) setf.exp FR_Two_N = GR_N_Biased
nop.f 0
- addl GR_Scratch1 = 0x063BF,r0
+ mov GR_min_den_exp = 0x0fc01 - 52 // Exponent of min denorm dble
}
{ .mfb
- addl GR_Scratch = 0x019C3F,r0
-(p6) fma.d.s0 FR_Result = FR_Floating_X,f1, f0
-(p6) br.ret.spnt b0
-};;
+ and GR_exp_X = GR_exp_mask, GR_signexp_X
+(p6) fma.d.s0 FR_Result = FR_Floating_X, f1, f0
+(p6) br.ret.spnt b0
+}
+;;
//
-// Create 2*big
-// Create 2**-big
-// Is N > 35000
-// Is N < -35000
// Raise Denormal operand flag with compare
-// Main path, create 2**N
+// Compute biased result exponent
//
{ .mfi
- setf.exp FR_NBig = GR_Scratch1
- nop.f 0
- cmp.ge p6, p0 = GR_N_as_int, GR_Big
-}
-{ .mfi
- setf.exp FR_Big = GR_Scratch
+ add GR_exp_Result = GR_exp_X, GR_N_as_int
fcmp.ge.s0 p0,p11 = FR_Floating_X,f0
- cmp.le p8, p0 = GR_N_as_int, GR_NBig
-};;
+ mov GR_neg_ov_limit = 0x303ff // Exponent for negative overflow
+}
+;;
//
-// Adjust 2**N if N was very small or very large
+// Do final operation
//
{ .mfi
- nop.m 0
-(p6) fma.s1 FR_Two_N = FR_Big,f1,f0
- nop.i 0
+ cmp.lt p7,p6 = GR_exp_Result, GR_max_exp // Test no overflow
+ fma.d.s0 FR_Result = FR_Two_N,FR_Norm_X,f0
+ cmp.lt p9,p0 = GR_exp_Result, GR_min_den_exp // Test sure underflow
}
-{ .mlx
- nop.m 999
- movl GR_Scratch = 0x00000000000303FF
-};;
+{ .mfb
+ nop.m 0
+ nop.f 0
+(p9) br.cond.spnt SCALBN_UNDERFLOW // Branch if certain underflow
+}
+;;
+{ .mib
+(p6) cmp.gt.unc p6,p8 = GR_exp_Result, GR_max_exp // Test sure overflow
+(p7) cmp.ge.unc p7,p9 = GR_exp_Result, GR_min_exp // Test no over/underflow
+(p7) br.ret.sptk b0 // Return from main path
+}
+;;
-{ .mfi
- nop.m 0
-(p8) fma.s1 FR_Two_N = FR_NBig,f1,f0
- nop.i 0
+{ .bbb
+(p6) br.cond.spnt SCALBN_OVERFLOW // Branch if certain overflow
+(p8) br.cond.spnt SCALBN_POSSIBLE_OVERFLOW // Branch if possible overflow
+(p9) br.cond.spnt SCALBN_POSSIBLE_UNDERFLOW // Branch if possible underflow
}
-{ .mlx
- nop.m 999
- movl GR_Scratch1= 0x00000000000103FF
-};;
+;;
-// Set up necessary status fields
+// Here if possible underflow.
+// Resulting exponent: 0x0fc01-52 <= exp_Result < 0x0fc01
+SCALBN_POSSIBLE_UNDERFLOW:
+//
+// Here if possible overflow.
+// Resulting exponent: 0x103fe = exp_Result
+SCALBN_POSSIBLE_OVERFLOW:
+
+// Set up necessary status fields
//
// S0 user supplied status
// S2 user supplied status + WRE + TD (Overflows)
// S3 user supplied status + FZ + TD (Underflows)
//
{ .mfi
- nop.m 999
+ nop.m 0
fsetc.s3 0x7F,0x41
- nop.i 999
+ nop.i 0
}
{ .mfi
- nop.m 999
+ nop.m 0
fsetc.s2 0x7F,0x42
- nop.i 999
-};;
+ nop.i 0
+}
+;;
//
-// Do final operation
+// Do final operation with s2 and s3
//
{ .mfi
- setf.exp FR_NBig = GR_Scratch
- fma.d.s0 FR_Result = FR_Two_N,FR_Norm_X,f0
- nop.i 999
+ setf.exp FR_NBig = GR_neg_ov_limit
+ fma.d.s3 FR_Result3 = FR_Two_N,FR_Norm_X,f0
+ nop.i 0
}
{ .mfi
- nop.m 999
- fma.d.s3 FR_Result3 = FR_Two_N,FR_Norm_X,f0
- nop.i 999
-};;
-{ .mfi
- setf.exp FR_Big = GR_Scratch1
- fma.d.s2 FR_Result2 = FR_Two_N,FR_Norm_X,f0
- nop.i 999
-};;
+ setf.exp FR_Big = GR_pos_ov_limit
+ fma.d.s2 FR_Result2 = FR_Two_N,FR_Norm_X,f0
+ nop.i 0
+}
+;;
// Check for overflow or underflow.
// Restore s3
// Restore s2
//
{ .mfi
- nop.m 0
+ nop.m 0
fsetc.s3 0x7F,0x40
- nop.i 999
+ nop.i 0
}
{ .mfi
- nop.m 0
+ nop.m 0
fsetc.s2 0x7F,0x40
- nop.i 999
-};;
+ nop.i 0
+}
+;;
//
// Is the result zero?
//
{ .mfi
- nop.m 999
+ nop.m 0
fclass.m p6, p0 = FR_Result3, 0x007
- nop.i 999
-}
+ nop.i 0
+}
{ .mfi
- addl GR_Tag = 176, r0
+ nop.m 0
fcmp.ge.s1 p7, p8 = FR_Result2 , FR_Big
- nop.i 0
-};;
+ nop.i 0
+}
+;;
//
// Detect masked underflow - Tiny + Inexact Only
//
{ .mfi
- nop.m 999
+ nop.m 0
(p6) fcmp.neq.unc.s1 p6, p0 = FR_Result , FR_Result2
- nop.i 999
-};;
+ nop.i 0
+}
+;;
//
// Is result bigger the allowed range?
// Branch out for underflow
//
{ .mfb
-(p6) addl GR_Tag = 177, r0
+ nop.m 0
(p8) fcmp.le.unc.s1 p9, p10 = FR_Result2 , FR_NBig
-(p6) br.cond.spnt SCALBN_UNDERFLOW
-};;
+(p6) br.cond.spnt SCALBN_UNDERFLOW
+}
+;;
//
// Branch out for overflow
//
-{ .mbb
- nop.m 0
-(p7) br.cond.spnt SCALBN_OVERFLOW
-(p9) br.cond.spnt SCALBN_OVERFLOW
-};;
+{ .bbb
+(p7) br.cond.spnt SCALBN_OVERFLOW
+(p9) br.cond.spnt SCALBN_OVERFLOW
+ br.ret.sptk b0 // Return from main path.
+}
+;;
-//
-// Return from main path.
-//
-{ .mfb
- nop.m 999
- nop.f 0
- br.ret.sptk b0;;
+// Here if result overflows
+SCALBN_OVERFLOW:
+{ .mib
+ alloc r32=ar.pfs,3,0,4,0
+ addl GR_Tag = 176, r0 // Set error tag for overflow
+ br.cond.sptk __libm_error_region // Call error support for overflow
}
+;;
-GLOBAL_LIBM_END(__libm_scalbn)
-__libm_error_region:
+// Here if result underflows
+SCALBN_UNDERFLOW:
+{ .mib
+ alloc r32=ar.pfs,3,0,4,0
+ addl GR_Tag = 177, r0 // Set error tag for underflow
+ br.cond.sptk __libm_error_region // Call error support for underflow
+}
+;;
+
+// Here if x=unorm
+SCALBN_UNORM:
+{ .mib
+ getf.exp GR_signexp_X = FR_Norm_X // Get signexp of normalized x
+ nop.i 0
+ br.cond.sptk SCALBN_COMMON // Return to main path
+}
+;;
-SCALBN_OVERFLOW:
-SCALBN_UNDERFLOW:
+
+GLOBAL_LIBM_END(__libm_scalbn)
+LOCAL_LIBM_ENTRY(__libm_error_region)
//
// Get stack address of N
//
.prologue
{ .mfi
- add GR_Parameter_Y=-32,sp
+ add GR_Parameter_Y=-32,sp
nop.f 0
.save ar.pfs,GR_SAVE_PFS
- mov GR_SAVE_PFS=ar.pfs
+ mov GR_SAVE_PFS=ar.pfs
}
//
-// Adjust sp
+// Adjust sp
//
{ .mfi
.fframe 64
- add sp=-64,sp
+ add sp=-64,sp
nop.f 0
- mov GR_SAVE_GP=gp
+ mov GR_SAVE_GP=gp
};;
//
-// Store N on stack in correct position
+// Store N on stack in correct position
// Locate the address of x on stack
//
{ .mmi
- st8 [GR_Parameter_Y] = GR_N_as_int,16
- add GR_Parameter_X = 16,sp
+ st8 [GR_Parameter_Y] = GR_N_as_int,16
+ add GR_Parameter_X = 16,sp
.save b0, GR_SAVE_B0
- mov GR_SAVE_B0=b0
+ mov GR_SAVE_B0=b0
};;
//
@@ -337,42 +408,42 @@ SCALBN_UNDERFLOW:
//
.body
{ .mib
- stfd [GR_Parameter_X] = FR_Norm_X
- add GR_Parameter_RESULT = 0,GR_Parameter_Y
+ stfd [GR_Parameter_X] = FR_Norm_X
+ add GR_Parameter_RESULT = 0,GR_Parameter_Y
nop.b 0
}
{ .mib
- stfd [GR_Parameter_Y] = FR_Result
+ stfd [GR_Parameter_Y] = FR_Result
add GR_Parameter_Y = -16,GR_Parameter_Y
- br.call.sptk b0=__libm_error_support#
+ br.call.sptk b0=__libm_error_support#
};;
//
// Get location of result on stack
//
{ .mmi
+ add GR_Parameter_RESULT = 48,sp
nop.m 0
- nop.m 0
- add GR_Parameter_RESULT = 48,sp
+ nop.i 0
};;
//
-// Get the new result
+// Get the new result
//
{ .mmi
- ldfd FR_Result = [GR_Parameter_RESULT]
+ ldfd FR_Result = [GR_Parameter_RESULT]
.restore sp
- add sp = 64,sp
- mov b0 = GR_SAVE_B0
+ add sp = 64,sp
+ mov b0 = GR_SAVE_B0
};;
//
// Restore gp, ar.pfs and return
//
{ .mib
- mov gp = GR_SAVE_GP
- mov ar.pfs = GR_SAVE_PFS
- br.ret.sptk b0
+ mov gp = GR_SAVE_GP
+ mov ar.pfs = GR_SAVE_PFS
+ br.ret.sptk b0
};;
LOCAL_LIBM_END(__libm_error_region)