Sandipan Das has submitted this change. (
https://gem5-review.googlesource.com/c/public/gem5/+/40929 )
Change subject: arch-power: Refactor rotate instructions
......................................................................
arch-power: Refactor rotate instructions
This renames the mask span fields and the rotate helper
of the base class.
Change-Id: I120006a0c052fcc34eb154a68d4b7f70a464df65
Signed-off-by: Sandipan Das <[email protected]>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40929
Reviewed-by: Boris Shingarov <[email protected]>
Maintainer: Boris Shingarov <[email protected]>
Tested-by: kokoro <[email protected]>
---
M src/arch/power/insts/integer.cc
M src/arch/power/insts/integer.hh
M src/arch/power/isa/decoder.isa
M src/arch/power/isa/formats/integer.isa
4 files changed, 19 insertions(+), 16 deletions(-)
Approvals:
Boris Shingarov: Looks good to me, approved; Looks good to me, approved
kokoro: Regressions pass
diff --git a/src/arch/power/insts/integer.cc
b/src/arch/power/insts/integer.cc
index 484354b..e59532d 100644
--- a/src/arch/power/insts/integer.cc
+++ b/src/arch/power/insts/integer.cc
@@ -676,7 +676,7 @@
}
// Print the shift, mask begin and mask end
- ss << ", " << (int) sh << ", " << mb << ", " << me;
+ ss << ", " << (int) sh << ", " << (int) mb << ", " << (int) me;
return ss.str();
}
diff --git a/src/arch/power/insts/integer.hh
b/src/arch/power/insts/integer.hh
index d655e08..f5a3968 100644
--- a/src/arch/power/insts/integer.hh
+++ b/src/arch/power/insts/integer.hh
@@ -623,15 +623,17 @@
/**
- * Class for integer rotate operations.
+ * Class for integer rotate operations with a shift amount obtained
+ * from a register or an immediate and the first and last bits of a
+ * mask obtained from immediates.
*/
class IntRotateOp : public IntShiftOp
{
protected:
- uint32_t mb;
- uint32_t me;
uint32_t fullMask;
+ uint8_t mb;
+ uint8_t me;
/// Constructor
IntRotateOp(const char *mnem, MachInst _machInst, OpClass __opClass)
@@ -646,11 +648,11 @@
}
}
- uint32_t
- rotateValue(uint32_t rs, uint32_t shift) const
+ inline uint32_t
+ rotate(uint32_t value, uint32_t shift) const
{
- uint32_t n = shift & 31;
- return (rs << n) | (rs >> (32 - n));
+ shift &= 31;
+ return (value << shift) | (value >> (32 - shift));
}
std::string generateDisassembly(
diff --git a/src/arch/power/isa/decoder.isa b/src/arch/power/isa/decoder.isa
index 2a21a48..75a7578 100644
--- a/src/arch/power/isa/decoder.isa
+++ b/src/arch/power/isa/decoder.isa
@@ -195,10 +195,9 @@
}
format IntRotateOp {
- 20: rlwimi({{ Ra = (rotateValue(Rs, sh) & fullMask) |
- (Ra & ~fullMask); }});
- 21: rlwinm({{ Ra = rotateValue(Rs, sh) & fullMask; }});
- 23: rlwnm({{ Ra = rotateValue(Rs, Rb) & fullMask; }});
+ 20: rlwimi({{ Ra = (rotate(Rs, sh) & fullMask) | (Ra & ~fullMask);
}});
+ 21: rlwinm({{ Ra = rotate(Rs, sh) & fullMask; }});
+ 23: rlwnm({{ Ra = rotate(Rs, Rb) & fullMask; }});
}
format IntImmLogicOp {
diff --git a/src/arch/power/isa/formats/integer.isa
b/src/arch/power/isa/formats/integer.isa
index 3cef9cc..1bdf639 100644
--- a/src/arch/power/isa/formats/integer.isa
+++ b/src/arch/power/isa/formats/integer.isa
@@ -488,15 +488,17 @@
}};
-// A special format for rotate instructions which use certain fields
-// from the instruction's binary encoding. We need two versions for each
-// instruction to deal with the Rc bit.
+// Integer instructions with or without immediate that perform rotate
+// operations. All instructions write to Ra and use Rs as a source
+// register. If immediate is not used, Rb is also used as a source
+// register. We need two versions for each instruction to deal with
+// the Rc bit.
def format IntRotateOp(code, inst_flags = []) {{
# The result is always in Ra
dict = {'result':'Ra'}
- # Setup the code for when Rc is set
+ # Code when Rc is set
code_rc1 = readXERCode + code + computeCR0Code % dict
# Generate the first class
--
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Gerrit-Project: public/gem5
Gerrit-Branch: develop
Gerrit-Change-Id: I120006a0c052fcc34eb154a68d4b7f70a464df65
Gerrit-Change-Number: 40929
Gerrit-PatchSet: 8
Gerrit-Owner: Sandipan Das <[email protected]>
Gerrit-Reviewer: Boris Shingarov <[email protected]>
Gerrit-Reviewer: Sandipan Das <[email protected]>
Gerrit-Reviewer: kokoro <[email protected]>
Gerrit-MessageType: merged
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