| Message ID | 20141118215928.GR1745@tucnak.redhat.com |
|---|---|
| State | New |
| Headers | show |
On November 18, 2014 10:59:28 PM CET, Jakub Jelinek <jakub@redhat.com> wrote: >Hi! > >The case ASHIFTRT: which is meant for this optimization is preceeded by >/* FALLTHRU */ from ROTATE cases, which can't be optimized this way. >Thus, this patch limits this optimization to ASHIFTRT. > >Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? OK. Thanks, Richard. >2014-11-18 Jakub Jelinek <jakub@redhat.com> > > PR rtl-optimization/63843 > * simplify-rtx.c (simplify_binary_operation_1) <case ASHIFTRT>: For > optimization of ashiftrt of subreg of lshiftrt, check that code > is ASHIFTRT. > > * gcc.c-torture/execute/pr63843.c: New test. > >--- gcc/simplify-rtx.c.jj 2014-11-18 10:17:01.000000000 +0100 >+++ gcc/simplify-rtx.c 2014-11-18 13:44:26.727792683 +0100 >@@ -3118,10 +3118,11 @@ simplify_binary_operation_1 (enum rtx_co > (subreg:M1 (ashiftrt:M2 (reg:M2) > (const_int <c1 + c2>)) > <low_part>). */ >- if (!VECTOR_MODE_P (mode) >+ if (code == ASHIFTRT >+ && !VECTOR_MODE_P (mode) > && SUBREG_P (op0) > && CONST_INT_P (op1) >- && (GET_CODE (SUBREG_REG (op0)) == LSHIFTRT) >+ && GET_CODE (SUBREG_REG (op0)) == LSHIFTRT > && !VECTOR_MODE_P (GET_MODE (SUBREG_REG (op0))) > && CONST_INT_P (XEXP (SUBREG_REG (op0), 1)) > && (GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (op0))) >--- gcc/testsuite/gcc.c-torture/execute/pr63843.c.jj 2014-11-18 >13:43:45.417544096 +0100 >+++ gcc/testsuite/gcc.c-torture/execute/pr63843.c 2014-11-18 >13:43:32.000000000 +0100 >@@ -0,0 +1,31 @@ >+/* PR rtl-optimization/63843 */ >+ >+static inline __attribute__ ((always_inline)) >+unsigned short foo (unsigned short v) >+{ >+ return (v << 8) | (v >> 8); >+} >+ >+unsigned short __attribute__ ((noinline, noclone, hot)) >+bar (unsigned char *x) >+{ >+ unsigned int a; >+ unsigned short b; >+ __builtin_memcpy (&a, &x[0], sizeof (a)); >+ a ^= 0x80808080U; >+ __builtin_memcpy (&x[0], &a, sizeof (a)); >+ __builtin_memcpy (&b, &x[2], sizeof (b)); >+ return foo (b); >+} >+ >+int >+main () >+{ >+ unsigned char x[8] = { 0x01, 0x01, 0x01, 0x01 }; >+ if (__CHAR_BIT__ == 8 >+ && sizeof (short) == 2 >+ && sizeof (int) == 4 >+ && bar (x) != 0x8181U) >+ __builtin_abort (); >+ return 0; >+} > > Jakub
--- gcc/simplify-rtx.c.jj 2014-11-18 10:17:01.000000000 +0100 +++ gcc/simplify-rtx.c 2014-11-18 13:44:26.727792683 +0100 @@ -3118,10 +3118,11 @@ simplify_binary_operation_1 (enum rtx_co (subreg:M1 (ashiftrt:M2 (reg:M2) (const_int <c1 + c2>)) <low_part>). */ - if (!VECTOR_MODE_P (mode) + if (code == ASHIFTRT + && !VECTOR_MODE_P (mode) && SUBREG_P (op0) && CONST_INT_P (op1) - && (GET_CODE (SUBREG_REG (op0)) == LSHIFTRT) + && GET_CODE (SUBREG_REG (op0)) == LSHIFTRT && !VECTOR_MODE_P (GET_MODE (SUBREG_REG (op0))) && CONST_INT_P (XEXP (SUBREG_REG (op0), 1)) && (GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (op0))) --- gcc/testsuite/gcc.c-torture/execute/pr63843.c.jj 2014-11-18 13:43:45.417544096 +0100 +++ gcc/testsuite/gcc.c-torture/execute/pr63843.c 2014-11-18 13:43:32.000000000 +0100 @@ -0,0 +1,31 @@ +/* PR rtl-optimization/63843 */ + +static inline __attribute__ ((always_inline)) +unsigned short foo (unsigned short v) +{ + return (v << 8) | (v >> 8); +} + +unsigned short __attribute__ ((noinline, noclone, hot)) +bar (unsigned char *x) +{ + unsigned int a; + unsigned short b; + __builtin_memcpy (&a, &x[0], sizeof (a)); + a ^= 0x80808080U; + __builtin_memcpy (&x[0], &a, sizeof (a)); + __builtin_memcpy (&b, &x[2], sizeof (b)); + return foo (b); +} + +int +main () +{ + unsigned char x[8] = { 0x01, 0x01, 0x01, 0x01 }; + if (__CHAR_BIT__ == 8 + && sizeof (short) == 2 + && sizeof (int) == 4 + && bar (x) != 0x8181U) + __builtin_abort (); + return 0; +}