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make: fix builds with clang by embedding required compiler-rt functions

K. Lange 11 months ago
parent
commit
88363fa19e
2 changed files with 524 additions and 3 deletions
  1. 7 3
      Makefile
  2. 517 0
      util/compiler-rt.S

+ 7 - 3
Makefile

@@ -70,9 +70,13 @@ RAMDISK_FILES= ${APPS_X} ${APPS_SH_X} ${LIBS_X} base/lib/ld.so base/lib/libm.so
 ifeq (,${USE_CLANG})
 KCC = $(TARGET_TRIPLET)-gcc
 LGCC = -lgcc
+EXTRALIB = 
 else
 KCC = clang --target=i686-elf -static -Ibase/usr/include -nostdinc -mno-sse
-LGCC = -lgcc
+LGCC = util/compiler-rt.o
+EXTRALIB = util/compiler-rt.o
+util/compiler-rt.o: util/compiler-rt.S
+	${KAS} ${ASFLAGS} $< -o $@
 endif
 KAS = $(TARGET_TRIPLET)-as
 KLD = $(TARGET_TRIPLET)-ld
@@ -98,7 +102,7 @@ KERNEL_ASMOBJS = $(filter-out kernel/symbols.o,$(patsubst %.S,%.o,$(wildcard ker
 
 # Kernel
 
-fatbase/kernel: ${KERNEL_ASMOBJS} ${KERNEL_OBJS} kernel/symbols.o
+fatbase/kernel: ${KERNEL_ASMOBJS} ${KERNEL_OBJS} kernel/symbols.o ${EXTRALIB}
 	${KCC} -T kernel/link.ld ${KCFLAGS} -nostdlib -o $@ ${KERNEL_ASMOBJS} ${KERNEL_OBJS} kernel/symbols.o ${LGCC}
 
 ##
@@ -109,7 +113,7 @@ fatbase/kernel: ${KERNEL_ASMOBJS} ${KERNEL_OBJS} kernel/symbols.o
 # build the kernel as a flat binary or load it with less-capable
 # multiboot loaders and still get symbols, which we need to
 # load kernel modules and link them properly.
-kernel/symbols.o: ${KERNEL_ASMOBJS} ${KERNEL_OBJS} util/generate_symbols.py
+kernel/symbols.o: ${KERNEL_ASMOBJS} ${KERNEL_OBJS} util/generate_symbols.py ${EXTRALIB}
 	-rm -f kernel/symbols.o
 	${KCC} -T kernel/link.ld ${KCFLAGS} -nostdlib -o .toaruos-kernel ${KERNEL_ASMOBJS} ${KERNEL_OBJS} ${LGCC}
 	${KNM} .toaruos-kernel -g | util/generate_symbols.py > kernel/symbols.S

+ 517 - 0
util/compiler-rt.S

@@ -0,0 +1,517 @@
+// This file contains assembly implementations of:
+//    __udivdi3
+//    __umoddi3
+// ... from LLVM's compiler-rt, for use with building
+// the ToaruOS kernel with a bare clang, with no need to link
+// to libgcc or compiler-rt directly. If more function
+// implementations are needed in the future, these should also
+// be included here.
+
+// ==============================================================================
+// The LLVM Project is under the Apache License v2.0 with LLVM Exceptions:
+// ==============================================================================
+// 
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+// ==============================================================================
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+// to be used under both.
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+// ==============================================================================
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+// Copyright (c) 2009-2019 by the contributors listed in CREDITS.TXT
+// 
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+// Copyright (c) 2009-2015 by the contributors listed in CREDITS.TXT
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+// THE SOFTWARE.
+.text
+.balign 4
+.globl __udivdi3
+__udivdi3:
+
+	pushl		%ebx
+	movl	 20(%esp),			%ebx	// Find the index i of the leading bit in b.
+	bsrl		%ebx,			%ecx	// If the high word of b is zero, jump to
+	jz			9f						// the code to handle that special case [9].
+
+	// High word of b is known to be non-zero on this branch
+
+	movl	 16(%esp),			%eax	// Construct bhi, containing bits [1+i:32+i] of b
+
+	shrl		%cl,			%eax	// Practically, this means that bhi is given by:
+	shrl		%eax					//
+	notl		%ecx					//		bhi = (high word of b) << (31 - i) |
+	shll		%cl,			%ebx	//			  (low word of b) >> (1 + i)
+	orl			%eax,			%ebx	//
+	movl	 12(%esp),			%edx	// Load the high and low words of a, and jump
+	movl	  8(%esp),			%eax	// to [1] if the high word is larger than bhi
+	cmpl		%ebx,			%edx	// to avoid overflowing the upcoming divide.
+	jae			1f
+
+	// High word of a is greater than or equal to (b >> (1 + i)) on this branch
+
+	divl		%ebx					// eax <-- qs, edx <-- r such that ahi:alo = bs*qs + r
+
+	pushl		%edi
+	notl		%ecx
+	shrl		%eax
+	shrl		%cl,			%eax	// q = qs >> (1 + i)
+	movl		%eax,			%edi
+	mull	 20(%esp)					// q*blo
+	movl	 12(%esp),			%ebx
+	movl	 16(%esp),			%ecx	// ECX:EBX = a
+	subl		%eax,			%ebx
+	sbbl		%edx,			%ecx	// ECX:EBX = a - q*blo
+	movl	 24(%esp),			%eax
+	imull		%edi,			%eax	// q*bhi
+	subl		%eax,			%ecx	// ECX:EBX = a - q*b
+	sbbl		$0,				%edi	// decrement q if remainder is negative
+	xorl		%edx,			%edx
+	movl		%edi,			%eax
+	popl		%edi
+	popl		%ebx
+	retl
+
+
+1:	// High word of a is greater than or equal to (b >> (1 + i)) on this branch
+
+	subl		%ebx,			%edx	// subtract bhi from ahi so that divide will not
+	divl		%ebx					// overflow, and find q and r such that
+										//
+										//		ahi:alo = (1:q)*bhi + r
+										//
+										// Note that q is a number in (31-i).(1+i)
+										// fix point.
+
+	pushl		%edi
+	notl		%ecx
+	shrl		%eax
+	orl			$0x80000000,	%eax
+	shrl		%cl,			%eax	// q = (1:qs) >> (1 + i)
+	movl		%eax,			%edi
+	mull	 20(%esp)					// q*blo
+	movl	 12(%esp),			%ebx
+	movl	 16(%esp),			%ecx	// ECX:EBX = a
+	subl		%eax,			%ebx
+	sbbl		%edx,			%ecx	// ECX:EBX = a - q*blo
+	movl	 24(%esp),			%eax
+	imull		%edi,			%eax	// q*bhi
+	subl		%eax,			%ecx	// ECX:EBX = a - q*b
+	sbbl		$0,				%edi	// decrement q if remainder is negative
+	xorl		%edx,			%edx
+	movl		%edi,			%eax
+	popl		%edi
+	popl		%ebx
+	retl
+
+
+9:	// High word of b is zero on this branch
+
+	movl	 12(%esp),			%eax	// Find qhi and rhi such that
+	movl	 16(%esp),			%ecx	//
+	xorl		%edx,			%edx	//		ahi = qhi*b + rhi	with	0 ≤ rhi < b
+	divl		%ecx					//
+	movl		%eax,			%ebx	//
+	movl	  8(%esp),			%eax	// Find qlo such that
+	divl		%ecx					//
+	movl		%ebx,			%edx	//		rhi:alo = qlo*b + rlo  with 0 ≤ rlo < b
+	popl		%ebx					//
+	retl								// and return qhi:qlo
+
+.text
+.balign 4
+.globl __umoddi3
+__umoddi3:
+
+	pushl		%ebx
+	movl	 20(%esp),			%ebx	// Find the index i of the leading bit in b.
+	bsrl		%ebx,			%ecx	// If the high word of b is zero, jump to
+	jz			9f						// the code to handle that special case [9].
+
+	// High word of b is known to be non-zero on this branch
+
+	movl	 16(%esp),			%eax	// Construct bhi, containing bits [1+i:32+i] of b
+
+	shrl		%cl,			%eax	// Practically, this means that bhi is given by:
+	shrl		%eax					//
+	notl		%ecx					//		bhi = (high word of b) << (31 - i) |
+	shll		%cl,			%ebx	//			  (low word of b) >> (1 + i)
+	orl			%eax,			%ebx	//
+	movl	 12(%esp),			%edx	// Load the high and low words of a, and jump
+	movl	  8(%esp),			%eax	// to [2] if the high word is larger than bhi
+	cmpl		%ebx,			%edx	// to avoid overflowing the upcoming divide.
+	jae			2f
+
+	// High word of a is greater than or equal to (b >> (1 + i)) on this branch
+
+	divl		%ebx					// eax <-- qs, edx <-- r such that ahi:alo = bs*qs + r
+
+	pushl		%edi
+	notl		%ecx
+	shrl		%eax
+	shrl		%cl,			%eax	// q = qs >> (1 + i)
+	movl		%eax,			%edi
+	mull	 20(%esp)					// q*blo
+	movl	 12(%esp),			%ebx
+	movl	 16(%esp),			%ecx	// ECX:EBX = a
+	subl		%eax,			%ebx
+	sbbl		%edx,			%ecx	// ECX:EBX = a - q*blo
+	movl	 24(%esp),			%eax
+	imull		%edi,			%eax	// q*bhi
+	subl		%eax,			%ecx	// ECX:EBX = a - q*b
+
+	jnc			1f						// if positive, this is the result.
+	addl	 20(%esp),			%ebx	// otherwise
+	adcl	 24(%esp),			%ecx	// ECX:EBX = a - (q-1)*b = result
+1:	movl		%ebx,			%eax
+	movl		%ecx,			%edx
+
+	popl		%edi
+	popl		%ebx
+	retl
+
+
+2:	// High word of a is greater than or equal to (b >> (1 + i)) on this branch
+
+	subl		%ebx,			%edx	// subtract bhi from ahi so that divide will not
+	divl		%ebx					// overflow, and find q and r such that
+										//
+										//		ahi:alo = (1:q)*bhi + r
+										//
+										// Note that q is a number in (31-i).(1+i)
+										// fix point.
+
+	pushl		%edi
+	notl		%ecx
+	shrl		%eax
+	orl			$0x80000000,	%eax
+	shrl		%cl,			%eax	// q = (1:qs) >> (1 + i)
+	movl		%eax,			%edi
+	mull	 20(%esp)					// q*blo
+	movl	 12(%esp),			%ebx
+	movl	 16(%esp),			%ecx	// ECX:EBX = a
+	subl		%eax,			%ebx
+	sbbl		%edx,			%ecx	// ECX:EBX = a - q*blo
+	movl	 24(%esp),			%eax
+	imull		%edi,			%eax	// q*bhi
+	subl		%eax,			%ecx	// ECX:EBX = a - q*b
+
+	jnc			3f						// if positive, this is the result.
+	addl	 20(%esp),			%ebx	// otherwise
+	adcl	 24(%esp),			%ecx	// ECX:EBX = a - (q-1)*b = result
+3:	movl		%ebx,			%eax
+	movl		%ecx,			%edx
+
+	popl		%edi
+	popl		%ebx
+	retl
+
+
+
+9:	// High word of b is zero on this branch
+
+	movl	 12(%esp),			%eax	// Find qhi and rhi such that
+	movl	 16(%esp),			%ecx	//
+	xorl		%edx,			%edx	//		ahi = qhi*b + rhi	with	0 ≤ rhi < b
+	divl		%ecx					//
+	movl		%eax,			%ebx	//
+	movl	  8(%esp),			%eax	// Find rlo such that
+	divl		%ecx					//
+	movl		%edx,			%eax	//		rhi:alo = qlo*b + rlo  with 0 ≤ rlo < b
+	popl		%ebx					//
+	xorl		%edx,			%edx	// and return 0:rlo
+	retl								//