Commit: MSP430: Add hardware multiply routines to libgcc

[Nick Clifton <nickc at redhat dot com>]

Hi Guys,

  I am applying the patch below to add libgcc functions to support
  hardware multiplies on the MSP430.

Cheers
  Nick
  
libgcc/ChangeLog
2014-03-06  Nick Clifton  <nickc@redhat.com>

	* config/msp430/t-msp430 (LIB2ADD): Add lib2hw_mul.S
	* config/msp430/lib2hw_mul.S: New: Hardware multiply routines.

Index: libgcc/config/msp430/lib2hw_mul.S
===================================================================
--- libgcc/config/msp430/lib2hw_mul.S	(revision 0)
+++ libgcc/config/msp430/lib2hw_mul.S	(working copy)
@@ -0,0 +1,226 @@
+;   Copyright (C) 2014 Free Software Foundation, Inc.
+;   Contributed by Red Hat.
+; 
+; This file is free software; you can redistribute it and/or modify it
+; under the terms of the GNU General Public License as published by the
+; Free Software Foundation; either version 3, or (at your option) any
+; later version.
+; 
+; This file is distributed in the hope that it will be useful, but
+; WITHOUT ANY WARRANTY; without even the implied warranty of
+; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+; General Public License for more details.
+; 
+; Under Section 7 of GPL version 3, you are granted additional
+; permissions described in the GCC Runtime Library Exception, version
+; 3.1, as published by the Free Software Foundation.
+;
+; You should have received a copy of the GNU General Public License and
+; a copy of the GCC Runtime Library Exception along with this program;
+; see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+; <http://www.gnu.org/licenses/>.
+
+.macro start_func name
+	.pushsection .text.\name,"ax",@progbits
+	.align 2
+	.global \name
+	.type \name , @function
+\name:
+	PUSH.W	sr			; Save current interrupt state
+	DINT				; Disable interrupts
+	NOP				; Account for latency
+.endm
+
+.macro end_func name
+#ifdef __MSP430X_LARGE__
+	POP.W  sr
+        RETA
+#else
+	RETI
+#endif
+	.size \name , . - \name
+	.popsection
+.endm
+
+.macro mult16 OP1, OP2, RESULT
+;* * 16-bit hardware multiply:  int16 = int16 * int16
+;*  
+;*   - Operand 1 is in R12
+;*   - Operand 2 is in R13
+;*   - Result is in R12
+;*
+;* To ensure that the multiply is performed atomically, interrupts are
+;* disabled upon routine entry.  Interrupt state is restored upon exit.
+;*
+;*   Registers used:  R12, R13
+;*
+;* Macro arguments are the memory locations of the hardware registers.
+	
+	MOV.W	r12, &\OP1		; Load operand 1 into multiplier
+	MOV.W	r13, &\OP2		; Load operand 2 which triggers MPY
+	MOV.W	&\RESULT, r12		; Move result into return register
+.endm
+
+.macro mult1632 OP1, OP2, RESULT_LO, RESULT_HI
+;* * 16-bit hardware multiply with a 32-bit result:
+;*	int32 = int16 * int16
+;* 	uint32 = uint16 * uint16
+;*  
+;*   - Operand 1 is in R12
+;*   - Operand 2 is in R13
+;*   - Result is in R12, R13
+;*
+;* To ensure that the multiply is performed atomically, interrupts are
+;* disabled upon routine entry.  Interrupt state is restored upon exit.
+;*
+;*   Registers used:  R12, R13
+;*
+;* Macro arguments are the memory locations of the hardware registers.
+	
+	MOV.W	r12, &\OP1		; Load operand 1 into multiplier
+	MOV.W	r13, &\OP2		; Load operand 2 which triggers MPY
+	MOV.W	&\RESULT_LO, r12	; Move low result into return register
+	MOV.W	&\RESULT_HI, r13	; Move high result into return register
+.endm
+
+.macro mult32 OP1, OP2, MAC_OP1, MAC_OP2, RESULT_LO, RESULT_HI
+;* * 32-bit hardware multiply with a 32-bit result using 16 multiply and accumulate:
+;*	int32 = int32 * int32
+;*  
+;*   - Operand 1 is in R12, R13
+;*   - Operand 2 is in R14, R15
+;*   - Result    is in R12, R13
+;*
+;* To ensure that the multiply is performed atomically, interrupts are
+;* disabled upon routine entry.  Interrupt state is restored upon exit.
+;*
+;*   Registers used:  R12, R13, R14, R15
+;*
+;* Macro arguments are the memory locations of the hardware registers.
+	
+	MOV.W	r12, &\OP1		; Load operand 1 Low into multiplier
+	MOV.W	r14, &\OP2		; Load operand 2 Low which triggers MPY
+	MOV.W	r12, &\MAC_OP1		; Load operand 1 Low into mac
+	MOV.W   &\RESULT_LO, r12	; Low 16-bits of result ready for return
+	MOV.W   &\RESULT_HI, &\RESULT_LO; MOV intermediate mpy high into low
+	MOV.W	r15, &\MAC_OP2		; Load operand 2 High, trigger MAC
+	MOV.W	r13, &\MAC_OP1		; Load operand 1 High
+	MOV.W	r14, &\MAC_OP2		; Load operand 2 Lo, trigger MAC
+	MOV.W	&\RESULT_LO, r13        ; Upper 16-bits result ready for return
+.endm
+
+
+.macro mult32_hw  OP1_LO  OP1_HI  OP2_LO  OP2_HI  RESULT_LO  RESULT_HI
+;* * 32-bit hardware multiply with a 32-bit result
+;*	int32 = int32 * int32
+;*  
+;*   - Operand 1 is in R12, R13
+;*   - Operand 2 is in R14, R15
+;*   - Result    is in R12, R13
+;*
+;* To ensure that the multiply is performed atomically, interrupts are
+;* disabled upon routine entry.  Interrupt state is restored upon exit.
+;*
+;*   Registers used:  R12, R13, R14, R15
+;*
+;* Macro arguments are the memory locations of the hardware registers.
+	
+	MOV.W	r12, &\OP1_LO		; Load operand 1 Low into multiplier
+	MOV.W	r13, &\OP1_HI		; Load operand 1 High into multiplier
+	MOV.W	r14, &\OP2_LO		; Load operand 2 Low into multiplier
+	MOV.W	r15, &\OP2_HI		; Load operand 2 High, trigger MPY
+	MOV.W	&\RESULT_LO, r12	; Ready low 16-bits for return
+	MOV.W   &\RESULT_HI, r13	; Ready high 16-bits for return
+.endm
+
+.macro mult3264_hw  OP1_LO  OP1_HI  OP2_LO  OP2_HI  RES0 RES1 RES2 RES3
+;* * 32-bit hardware multiply with a 64-bit result
+;*	int64 = int32 * int32
+;*	uint64 = uint32 * uint32
+;*  
+;*   - Operand 1 is in R12, R13
+;*   - Operand 2 is in R14, R15
+;*   - Result    is in R12, R13, R14, R15
+;*
+;* To ensure that the multiply is performed atomically, interrupts are
+;* disabled upon routine entry.  Interrupt state is restored upon exit.
+;*
+;*   Registers used:  R12, R13, R14, R15
+;*
+;* Macro arguments are the memory locations of the hardware registers.
+	
+	MOV.W	r12, &\OP1_LO		; Load operand 1 Low into multiplier
+	MOV.W	r13, &\OP1_HI		; Load operand 1 High into multiplier
+	MOV.W	r14, &\OP2_LO		; Load operand 2 Low into multiplier
+	MOV.W	r15, &\OP2_HI		; Load operand 2 High, trigger MPY
+	MOV.W	&\RES0, R12		; Ready low 16-bits for return
+	MOV.W   &\RES1, R13		; 
+	MOV.W	&\RES2, R14		; 
+	MOV.W   &\RES3, R15		; Ready high 16-bits for return
+.endm
+
+
+;;  First generation MSP430 hardware multiplies ....
+
+.set MPY_OP1,   0x0130
+.set MPY_OP1_S, 0x0132
+.set MAC_OP1, 	0x0134
+.set MPY_OP2, 	0x0138
+.set MAC_OP2, 	0x0138
+.set RESULT_LO, 0x013A
+.set RESULT_HI, 0x013C
+	
+	start_func __mulhi2
+	mult16 MPY_OP1, MPY_OP2, RESULT_LO
+	end_func __mulhi2
+
+	start_func __mulsihi2
+	mult1632 MPY_OP1_S, MPY_OP2, RESULT_LO, RESULT_HI
+	end_func __mulsihi2
+
+	start_func __umulsihi2
+	mult1632 MPY_OP1, MPY_OP2, RESULT_LO, RESULT_HI
+	end_func __umulsihi2
+
+	start_func __mulsi2
+	mult32 MPY_OP1, MPY_OP2, MAC_OP1, MAC_OP2, RESULT_LO, RESULT_HI
+	end_func __mulsi2
+
+	start_func __mulsi2_hw32
+	mult32_hw 0x0140, 0x0142, 0x0150, 0x0152, 0x0154, 0x0156
+	end_func __mulsi2_hw32
+
+	start_func __muldisi2_hw32
+	mult3264_hw 0x0144, 0x146, 0x0150, 0x0152, 0x0154, 0x0156, 0x0158, 0x015A
+	end_func __muldisi2_hw32
+
+	start_func __umuldisi2_hw32
+	mult3264_hw 0x0140, 0x142, 0x0150, 0x0152, 0x0154, 0x0156, 0x0158, 0x015A
+	end_func __umuldisi2_hw32
+	
+/* The F5xxx series of MCUs support the same 16-bit hardware
+   multiply, but it is accessed from different memory registers.  */
+	
+	start_func __mulhi2_f5
+	mult16 0x04C0, 0x04C8, 0x04CA
+	end_func __mulhi2_f5
+
+	start_func __mulsihi2_f5
+	mult1632 0x04C2, 0x04C8, 0x04CA, 0x04CC
+	end_func __mulsihi2_f5
+	
+	start_func __umulsihi2_f5
+	mult1632 0x04C0, 0x04C8, 0x04CA, 0x04CC
+	end_func __umulsihi2_f5
+
+	start_func __mulsi2_f5
+	mult32_hw 0x04D0, 0x04D2, 0x04E0, 0x04E2, 0x04E4, 0x04E6
+	end_func __mulsi2_f5
+	
+	start_func __muldisi2_f5
+	mult3264_hw 0x04D4, 0x04D6, 0x04E0, 0x04E2, 0x04E4, 0x04E6, 0x04E8, 0x04EA
+	end_func __muldisi2_f5
+	
+	start_func __umuldisi2_f5
+	mult3264_hw 0x04D0, 0x04D2, 0x04E0, 0x04E2, 0x04E4, 0x04E6, 0x04E8, 0x04EA
+	end_func __umuldisi2_f5
Index: libgcc/config/msp430/t-msp430
===================================================================
--- libgcc/config/msp430/t-msp430	(revision 208372)
+++ libgcc/config/msp430/t-msp430	(working copy)
@@ -35,6 +35,7 @@
 	$(srcdir)/config/msp430/srai.S \
 	$(srcdir)/config/msp430/srli.S \
 	$(srcdir)/config/msp430/cmpsi2.S \
+	$(srcdir)/config/msp430/lib2hw_mul.S \
 	$(srcdir)/config/msp430/floatunhisf.c \
 	$(srcdir)/config/msp430/floatunhidf.c \
 	$(srcdir)/config/msp430/floathidf.c \