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| author | Richard Stallman <rms@gnu.org> | 1993-05-02 12:43:15 +0000 |
|---|---|---|
| committer | Richard Stallman <rms@gnu.org> | 1993-05-02 12:43:15 +0000 |
| commit | 2e794ee866f33007c5759bbb3b8d1f970b35adaa (patch) | |
| tree | ded0d90e309dc81fc04febbb338027d67648afad /gcc | |
| parent | 64685ffacf290aca816acc9a044bfa6ea0cc0725 (diff) | |
| download | gcc-2e794ee866f33007c5759bbb3b8d1f970b35adaa.zip gcc-2e794ee866f33007c5759bbb3b8d1f970b35adaa.tar.gz gcc-2e794ee866f33007c5759bbb3b8d1f970b35adaa.tar.bz2 | |
(record_jump_cond): Use mode of op0 or op1, not MODE,
when testing for narrowing or widening subregs.
From-SVN: r4301
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/cse.c | 17 |
1 files changed, 13 insertions, 4 deletions
@@ -5490,8 +5490,10 @@ record_jump_cond (code, mode, op0, op1, reversed_nonequality) true for all smaller modes whether or not there is a SUBREG, but is not worth testing for with no SUBREG. */ + /* Note that GET_MODE (op0) may not equal MODE. */ if (code == EQ && GET_CODE (op0) == SUBREG - && GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0)))) + && (GET_MODE_SIZE (GET_MODE (op0)) + > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0))))) { enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0)); rtx tem = gen_lowpart_if_possible (inner_mode, op1); @@ -5502,7 +5504,8 @@ record_jump_cond (code, mode, op0, op1, reversed_nonequality) } if (code == EQ && GET_CODE (op1) == SUBREG - && GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1)))) + && (GET_MODE_SIZE (GET_MODE (op1)) + > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1))))) { enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1)); rtx tem = gen_lowpart_if_possible (inner_mode, op0); @@ -5515,9 +5518,14 @@ record_jump_cond (code, mode, op0, op1, reversed_nonequality) /* Similarly, if this is an NE comparison, and either is a SUBREG making a smaller mode, we know the whole thing is also NE. */ + /* Note that GET_MODE (op0) may not equal MODE; + if we test MODE instead, we can get an infinite recursion + alternating between two modes each wider than MODE. */ + if (code == NE && GET_CODE (op0) == SUBREG && subreg_lowpart_p (op0) - && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0)))) + && (GET_MODE_SIZE (GET_MODE (op0)) + < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0))))) { enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0)); rtx tem = gen_lowpart_if_possible (inner_mode, op1); @@ -5529,7 +5537,8 @@ record_jump_cond (code, mode, op0, op1, reversed_nonequality) if (code == NE && GET_CODE (op1) == SUBREG && subreg_lowpart_p (op1) - && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1)))) + && (GET_MODE_SIZE (GET_MODE (op1)) + < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1))))) { enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1)); rtx tem = gen_lowpart_if_possible (inner_mode, op0); |