yann@1: [lightly edited to fit my patch directory - dank]
yann@1: 
yann@1: From: kaz Kojima <kkojima@rr.iij4u.or.jp>
yann@1: Date: Sat, 09 Aug 2003 09:46:21 +0900
yann@1: To: dank@kegel.com
yann@1: 
yann@1: Hi Dan,
yann@1: 
yann@1: I've come back from the vacation and looked glibc string test
yann@1: failures on sh4. This looks a gcc problem. gcc-3.3/3.4 doesn't
yann@1: compile these tests correctly. The attached testcase aborts on
yann@1: gcc-3.3/3.4 -O2 but exits normally gcc-3.2 and gcc-3.0.
yann@1: The option -O2 is not essential but it makes the testcase small.
yann@1: The failed string tests include the same pattern of the code with
yann@1: f=random to generate ramdom strings but they get strings with
yann@1: embedded NULL characters :-(
yann@1: 
yann@1: ...
yann@1: I've got a workaround below for this bug, though it might merely
yann@1: paper over the real bug. Anyway, I'd like to send a PR for this.
yann@1: 
yann@1: Regards,
yann@1: 	kaz
yann@1: --
yann@1: int val = 0xff00;
yann@1: 
yann@1: int f (void) { return val; }
yann@1: 
yann@1: unsigned char a[1];
yann@1: 
yann@1: void
yann@1: foo (void)
yann@1: {
yann@1:   a[0] = f () & 255;
yann@1: 
yann@1:   if (!a[0])
yann@1:     a[0] = f () & 255;
yann@1: 
yann@1:   if (!a[0])
yann@1:     a[0] = 1 + (f () & 127);
yann@1: }
yann@1: 
yann@1: int
yann@1: main (int argc, char **argv)
yann@1: {
yann@1:   foo ();
yann@1:   if (!a[0])
yann@1:     abort ();
yann@1: 
yann@1:   return 0;
yann@1: }
yann@1: 
yann@1: --
yann@1: 
yann@1: diff -u3prN ORIG/gcc/gcc/config/sh/sh.c LOCAL/gcc/gcc/config/sh/sh.c
yann@1: --- gcc/gcc/config/sh/sh.c.old	Fri Aug  8 18:39:02 2003
yann@1: +++ gcc/gcc/config/sh/sh.c	Fri Aug  8 22:31:02 2003
yann@1: @@ -6657,6 +6657,19 @@ arith_reg_dest (op, mode)
yann@1:    return arith_reg_operand (op, mode);
yann@1:  }
yann@1:  
yann@1: +/* Like above, but for SImode compare destinations: forbid paradoxical
yann@1: +   subregs, because it would get the combiner confused.  */
yann@1: +int
yann@1: +arith_reg_cmp_dest (op, mode)
yann@1: +     rtx op;
yann@1: +     enum machine_mode mode;
yann@1: +{
yann@1: +  if (mode == SImode && GET_CODE (op) == SUBREG
yann@1: +      && GET_MODE_SIZE (GET_MODE (SUBREG_REG (op))) < 4)
yann@1: +    return 0;
yann@1: +  return arith_reg_operand (op, mode);
yann@1: +}
yann@1: +
yann@1:  int
yann@1:  int_gpr_dest (op, mode)
yann@1:       rtx op;
yann@1: diff -u3prN ORIG/gcc/gcc/config/sh/sh.h LOCAL/gcc/gcc/config/sh/sh.h
yann@1: --- gcc/gcc/config/sh/sh.h.old	Fri Aug  8 18:39:02 2003
yann@1: +++ gcc/gcc/config/sh/sh.h	Fri Aug  8 22:31:02 2003
yann@1: @@ -3365,6 +3365,7 @@ extern int rtx_equal_function_value_matt
yann@1:    {"and_operand", {SUBREG, REG, CONST_INT}},				\
yann@1:    {"any_register_operand", {SUBREG, REG}},				\
yann@1:    {"arith_operand", {SUBREG, REG, CONST_INT}},				\
yann@1: +  {"arith_reg_cmp_dest", {SUBREG, REG}},				\
yann@1:    {"arith_reg_dest", {SUBREG, REG}},					\
yann@1:    {"arith_reg_operand", {SUBREG, REG}},					\
yann@1:    {"arith_reg_or_0_operand", {SUBREG, REG, CONST_INT, CONST_VECTOR}},	\
yann@1: 
yann@1: --- gcc-3.3/gcc/config/sh/sh.md.orig	Tue Apr 15 10:06:10 2003
yann@1: +++ gcc-3.3/gcc/config/sh/sh.md	Sat Aug  9 22:31:13 2003
yann@1: @@ -616,7 +616,7 @@
yann@1:  
yann@1:  (define_insn ""
yann@1:    [(set (reg:SI T_REG)
yann@1: -	(eq:SI (and:SI (match_operand:SI 0 "arith_reg_operand" "z,r")
yann@1: +	(eq:SI (and:SI (match_operand:SI 0 "arith_reg_cmp_dest" "z,r")
yann@1:  		       (match_operand:SI 1 "arith_operand" "L,r"))
yann@1:  	       (const_int 0)))]
yann@1:    "TARGET_SH1"
yann@1: @@ -631,7 +631,7 @@
yann@1:  
yann@1:  (define_insn "cmpeqsi_t"
yann@1:    [(set (reg:SI T_REG)
yann@1: -	(eq:SI (match_operand:SI 0 "arith_reg_operand" "r,z,r")
yann@1: +	(eq:SI (match_operand:SI 0 "arith_reg_cmp_dest" "r,z,r")
yann@1:  	       (match_operand:SI 1 "arith_operand" "N,rI,r")))]
yann@1:    "TARGET_SH1"
yann@1:    "@
yann@1: @@ -642,7 +642,7 @@
yann@1:  
yann@1:  (define_insn "cmpgtsi_t"
yann@1:    [(set (reg:SI T_REG)
yann@1: -	(gt:SI (match_operand:SI 0 "arith_reg_operand" "r,r")
yann@1: +	(gt:SI (match_operand:SI 0 "arith_reg_cmp_dest" "r,r")
yann@1:  	       (match_operand:SI 1 "arith_reg_or_0_operand" "r,N")))]
yann@1:    "TARGET_SH1"
yann@1:    "@
yann@1: @@ -652,7 +652,7 @@
yann@1:  
yann@1:  (define_insn "cmpgesi_t"
yann@1:    [(set (reg:SI T_REG)
yann@1: -	(ge:SI (match_operand:SI 0 "arith_reg_operand" "r,r")
yann@1: +	(ge:SI (match_operand:SI 0 "arith_reg_cmp_dest" "r,r")
yann@1:  	       (match_operand:SI 1 "arith_reg_or_0_operand" "r,N")))]
yann@1:    "TARGET_SH1"
yann@1:    "@
yann@1: @@ -666,7 +666,7 @@
yann@1:  
yann@1:  (define_insn "cmpgeusi_t"
yann@1:    [(set (reg:SI T_REG)
yann@1: -	(geu:SI (match_operand:SI 0 "arith_reg_operand" "r")
yann@1: +	(geu:SI (match_operand:SI 0 "arith_reg_cmp_dest" "r")
yann@1:  		(match_operand:SI 1 "arith_reg_operand" "r")))]
yann@1:    "TARGET_SH1"
yann@1:    "cmp/hs	%1,%0"
yann@1: @@ -674,7 +674,7 @@
yann@1:  
yann@1:  (define_insn "cmpgtusi_t"
yann@1:    [(set (reg:SI T_REG)
yann@1: -	(gtu:SI (match_operand:SI 0 "arith_reg_operand" "r")
yann@1: +	(gtu:SI (match_operand:SI 0 "arith_reg_cmp_dest" "r")
yann@1:  		(match_operand:SI 1 "arith_reg_operand" "r")))]
yann@1:    "TARGET_SH1"
yann@1:    "cmp/hi	%1,%0"