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104 lines
2.7 KiB
Plaintext
104 lines
2.7 KiB
Plaintext
TODO:
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* gpr0 allocation
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* implement do-loop -> bdnz transform
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* implement powerpc-64 for darwin
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* use stfiwx in float->int
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* be able to combine sequences like the following into 2 instructions:
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lis r2, ha16(l2__ZTV4Cell)
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la r2, lo16(l2__ZTV4Cell)(r2)
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addi r2, r2, 8
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* Teach LLVM how to codegen this:
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unsigned short foo(float a) { return a; }
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as:
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_foo:
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fctiwz f0,f1
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stfd f0,-8(r1)
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lhz r3,-2(r1)
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blr
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not:
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_foo:
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fctiwz f0, f1
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stfd f0, -8(r1)
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lwz r2, -4(r1)
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rlwinm r3, r2, 0, 16, 31
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blr
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* Support 'update' load/store instructions. These are cracked on the G5, but
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are still a codesize win.
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* Add a custom legalizer for the GlobalAddress node, to move the funky darwin
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stub stuff from the instruction selector to the legalizer (exposing low-level
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operations to the dag for optzn. For example, we want to codegen this:
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int A = 0;
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void B() { A++; }
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as:
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lis r9,ha16(_A)
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lwz r2,lo16(_A)(r9)
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addi r2,r2,1
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stw r2,lo16(_A)(r9)
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not:
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lis r2, ha16(_A)
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lwz r2, lo16(_A)(r2)
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addi r2, r2, 1
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lis r3, ha16(_A)
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stw r2, lo16(_A)(r3)
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* should hint to the branch select pass that it doesn't need to print the
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second unconditional branch, so we don't end up with things like:
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b .LBBl42__2E_expand_function_8_674 ; loopentry.24
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b .LBBl42__2E_expand_function_8_42 ; NewDefault
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b .LBBl42__2E_expand_function_8_42 ; NewDefault
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===-------------------------------------------------------------------------===
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* Codegen this:
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void test2(int X) {
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if (X == 0x12345678) bar();
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}
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as:
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xoris r0,r3,0x1234
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cmpwi cr0,r0,0x5678
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beq cr0,L6
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not:
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lis r2, 4660
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ori r2, r2, 22136
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cmpw cr0, r3, r2
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bne .LBB_test2_2
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===-------------------------------------------------------------------------===
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Lump the constant pool for each function into ONE pic object, and reference
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pieces of it as offsets from the start. For functions like this (contrived
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to have lots of constants obviously):
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double X(double Y) { return (Y*1.23 + 4.512)*2.34 + 14.38; }
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We generate:
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_X:
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lis r2, ha16(.CPI_X_0)
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lfd f0, lo16(.CPI_X_0)(r2)
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lis r2, ha16(.CPI_X_1)
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lfd f2, lo16(.CPI_X_1)(r2)
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fmadd f0, f1, f0, f2
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lis r2, ha16(.CPI_X_2)
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lfd f1, lo16(.CPI_X_2)(r2)
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lis r2, ha16(.CPI_X_3)
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lfd f2, lo16(.CPI_X_3)(r2)
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fmadd f1, f0, f1, f2
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blr
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It would be better to materialize .CPI_X into a register, then use immediates
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off of the register to avoid the lis's. This is even more important in PIC
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mode.
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===-------------------------------------------------------------------------===
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